# SellersCalc — E-commerce Calculators

> Free break-even ROAS/ACOS calculators for e-commerce merchants running
> paid ads. Each calculator shows its formula and assumptions inline;
> platform variants carry that platform's real fee structure.
> Fee assumptions last verified 2026-07-23. Estimates only.

## Calculators

- [Break-even ROAS Calculator](https://www.sellerscalc.com/break-even-roas-calculator):
  generic, any platform — price, COGS and per-order costs in; break-even
  ROAS, break-even ACOS, target ROAS and contribution margin out.
- [Amazon Break-even ACOS Calculator](https://www.sellerscalc.com/amazon-acos-calculator): break-even ACOS calculator for Amazon sellers. Enter price, COGS, referral and FBA fees to see the exact ACOS ceiling for profitable Sponsored Products ads.
- [Shopify Break-even ROAS Calculator](https://www.sellerscalc.com/shopify-roas-calculator): break-even ROAS calculator for Shopify stores. Payment processing, shipping and fulfillment included — set Meta and Google targets that actually profit.
- [TikTok Shop Break-even ROAS Calculator](https://www.sellerscalc.com/tiktok-shop-roas-calculator): break-even ROAS calculator for TikTok Shop sellers. Accounts for marketplace commission and affiliate cuts so your ads and creator spend stay profitable.
- [Dropshipping Break-even ROAS Calculator](https://www.sellerscalc.com/dropshipping-roas-calculator): break-even ROAS calculator for dropshipping. Supplier price, supplier shipping and processing fees included — see the ROAS your ads must clear to profit.
- [Etsy Break-even ROAS Calculator](https://www.sellerscalc.com/etsy-roas-calculator): break-even ROAS calculator for Etsy sellers. Transaction, payment processing and listing fees included — see what Etsy Ads must return before you profit.
- [Google Ads ROAS Calculator](https://www.sellerscalc.com/google-ads-roas-calculator): Google Ads ROAS calculator: enter price and per-order costs to get the break-even ROAS your Shopping and Search campaigns must clear to profit.
- [Facebook Ads ROAS Calculator](https://www.sellerscalc.com/facebook-ads-roas-calculator): Facebook Ads ROAS calculator: enter price and per-order costs to get the break-even ROAS your Meta and Instagram campaigns must clear to profit.

### Advertising & ROAS

- [Advertising & ROAS calculators — category hub](https://www.sellerscalc.com/advertising): Break-even and target math for paid traffic: ROAS, ACOS, budgets and click economics.
- [ROAS Calculator](https://www.sellerscalc.com/roas-calculator): ROAS calculator: enter ad revenue and ad spend to get your return on ad spend, the equivalent ACOS, and revenue earned per dollar of advertising.
- [ACOS Calculator](https://www.sellerscalc.com/acos-calculator): ACOS calculator: enter ad spend and attributed sales to get your advertising cost of sales percentage and the equivalent ROAS for the same campaign.
- [Target ROAS Calculator](https://www.sellerscalc.com/target-roas-calculator): target ROAS calculator: enter price, per-order costs and the margin you want to keep to get the ROAS to aim for, break-even ROAS and allowable ad spend.
- [CPC Calculator](https://www.sellerscalc.com/cpc-calculator): CPC calculator: enter total ad spend and the clicks it bought to get your average cost per click and how many visitors each $100 of budget delivers.
- [CPM Calculator](https://www.sellerscalc.com/cpm-calculator): CPM calculator: enter ad spend and impressions to get your cost per 1,000 impressions and how many impressions each $10 of ad budget is buying you.
- [CPA Calculator](https://www.sellerscalc.com/cpa-calculator): CPA calculator: enter ad spend and the conversions it produced to get your cost per acquisition and how many customers each $100 of budget delivers.
- [CTR Calculator](https://www.sellerscalc.com/ctr-calculator): CTR calculator: enter clicks and impressions to get your click-through rate percentage and clicks per 1,000 impressions — the ad creative scoreboard.
- [TACOS Calculator](https://www.sellerscalc.com/tacos-calculator): TACOS calculator: enter ad spend and total revenue to get total advertising cost of sales, plus the share of revenue still arriving organically.
- [Ad Budget Calculator](https://www.sellerscalc.com/ad-budget-calculator): ad budget calculator: enter your monthly revenue goal, target ROAS and average order value to get the required ad budget and expected order volume.
- [PPC Profit Calculator](https://www.sellerscalc.com/ppc-profit-calculator): PPC profit calculator: enter price, product cost and ad spend per sale to see the profit each paid order really makes and your margin after advertising.
- [ROAS to ACOS Converter](https://www.sellerscalc.com/roas-to-acos-converter): ROAS to ACOS converter: enter any ROAS multiplier to get the equivalent ACOS percentage and revenue per ad dollar — the same campaign in both languages.
- [CPM to CPC Calculator](https://www.sellerscalc.com/cpm-to-cpc-calculator): CPM to CPC calculator: enter your CPM and click-through rate to get the effective cost per click your impressions are producing, plus clicks per 1,000.

### Pricing & Margins

- [Pricing & Margins calculators — category hub](https://www.sellerscalc.com/pricing): Margins, markups, discounts and break-even points — the math that sets every price.
- [Profit Margin Calculator](https://www.sellerscalc.com/profit-margin-calculator): profit margin calculator for e-commerce. Enter revenue and cost to get your margin percentage, profit per sale, and the equivalent markup instantly.
- [Markup Calculator](https://www.sellerscalc.com/markup-calculator): markup calculator: enter product cost and markup percentage to get the selling price, profit per unit, and the profit margin that markup really gives you.
- [Selling Price Calculator](https://www.sellerscalc.com/selling-price-calculator): selling price calculator: enter your product cost and the profit margin you want to keep, and get the exact price to charge plus the markup it implies.
- [Discount Calculator](https://www.sellerscalc.com/discount-calculator): discount calculator: enter the original price and discount percentage to get the sale price and savings — and see what the markdown does to your margin.
- [Break-even Units Calculator](https://www.sellerscalc.com/break-even-units-calculator): break-even point calculator: enter fixed costs, price and variable cost per unit to see exactly how many sales cover your costs and the revenue that takes.
- [Margin vs Markup Calculator](https://www.sellerscalc.com/margin-vs-markup-calculator): margin vs markup calculator: enter cost and selling price to see profit margin and markup side by side — and stop the pricing mistake of mixing them up.
- [Keystone Pricing Calculator](https://www.sellerscalc.com/keystone-pricing-calculator): keystone pricing calculator: enter your unit cost to get the classic double-cost retail price, plus the profit per unit and the 50% margin it locks in.
- [Wholesale Price Calculator](https://www.sellerscalc.com/wholesale-price-calculator): wholesale price calculator: enter retail price, wholesale discount and unit cost to get your wholesale price, the margin you keep, and profit per unit.
- [GMROI Calculator](https://www.sellerscalc.com/gmroi-calculator): GMROI calculator: enter annual gross margin dollars and average inventory cost to see your gross margin return on inventory — profit per dollar invested.
- [Price Increase Calculator](https://www.sellerscalc.com/price-increase-calculator): price increase calculator: enter your current price, planned increase and unit cost to see the new price, your improved margin, and extra profit per unit.
- [Bundle Pricing Calculator](https://www.sellerscalc.com/bundle-pricing-calculator): bundle pricing calculator: enter the combined item value, bundle discount and total cost to get the bundle price, the customer savings, and your margin.
- [Unit Price Calculator](https://www.sellerscalc.com/unit-price-calculator): unit price calculator: divide any pack price by the number of units to get the true price per unit — and compare pack sizes or multipacks in seconds.
- [Gross Profit Calculator](https://www.sellerscalc.com/gross-profit-calculator): gross profit calculator: subtract cost of goods sold from revenue to get your gross profit in dollars and your gross margin percentage in one step.
- [VAT Price Calculator](https://www.sellerscalc.com/vat-price-calculator): VAT calculator: enter a net price and VAT rate to get the gross price customers pay and the VAT amount — essential for selling into the UK and EU.

### Marketplace & Payment Fees

- [Marketplace & Payment Fees calculators — category hub](https://www.sellerscalc.com/fees): What Amazon, Etsy, eBay, Shopify and payment processors really take from each sale.
- [Amazon FBA Profit Calculator](https://www.sellerscalc.com/amazon-fba-profit-calculator): Amazon FBA profit calculator: enter your price, product cost, referral fee and FBA fee to see net profit per unit, margin, and total Amazon fees.
- [Amazon Referral Fee Calculator](https://www.sellerscalc.com/amazon-referral-fee-calculator): Amazon referral fee calculator: enter your selling price and category rate to see the exact referral fee Amazon takes and what you keep per sale.
- [Etsy Fee Calculator](https://www.sellerscalc.com/etsy-fee-calculator): Etsy fee calculator: enter price and shipping to see the transaction fee, payment processing, and listing fee — plus your net proceeds and true fee rate.
- [eBay Fee Calculator](https://www.sellerscalc.com/ebay-fee-calculator): eBay fee calculator: enter your sale price and final value fee rate to see total eBay fees, your net proceeds, and the effective percentage taken.
- [PayPal Fee Calculator](https://www.sellerscalc.com/paypal-fee-calculator): PayPal fee calculator: see the fee on any payment, what you keep after 3.49% + $0.49, and exactly how much to invoice so you net your target amount.
- [Stripe Fee Calculator](https://www.sellerscalc.com/stripe-fee-calculator): Stripe fee calculator: see the 2.9% + $0.30 fee on any charge, your net payout, and the exact amount to charge so you receive your desired net.
- [Shopify Fee Calculator](https://www.sellerscalc.com/shopify-fee-calculator): Shopify fee calculator: enter your order value and plan rate to see the Shopify Payments fee per order, your net proceeds, and the effective rate.
- [Square Fee Calculator](https://www.sellerscalc.com/square-fee-calculator): Square fee calculator: enter any transaction amount and rate to see the exact Square processing fee and the net amount deposited to your account.
- [TikTok Shop Fee Calculator](https://www.sellerscalc.com/tiktok-shop-fee-calculator): TikTok Shop fee calculator: enter your sale price and referral commission rate to see the platform fee per order and the proceeds you actually keep.
- [Walmart Marketplace Fee Calculator](https://www.sellerscalc.com/walmart-fee-calculator): Walmart Marketplace fee calculator: enter your sale price and category referral rate to see the fee per order and the proceeds you keep as a seller.
- [Mercari Fee Calculator](https://www.sellerscalc.com/mercari-fee-calculator): Mercari fee calculator: enter your sale price to see the selling fee plus payment processing charge and the exact payout you keep after both.
- [Poshmark Fee Calculator](https://www.sellerscalc.com/poshmark-fee-calculator): Poshmark fee calculator: enter your sale price to apply the $2.95 flat fee under $15 or 20% commission above it, and see your exact earnings.
- [Depop Fee Calculator](https://www.sellerscalc.com/depop-fee-calculator): Depop fee calculator: enter your sale price, selling fee and payment processing rate to see total Depop fees and the payout you keep per sale.
- [Gumroad Fee Calculator](https://www.sellerscalc.com/gumroad-fee-calculator): Gumroad fee calculator: enter your product price and fee rate to see the platform cut per sale and the payout you keep on digital products.
- [Amazon Storage Fee Calculator](https://www.sellerscalc.com/amazon-storage-fee-calculator): Amazon FBA storage fee calculator: enter units, volume per unit and the monthly rate to get your monthly FBA storage cost and the storage cost per unit.
- [Shopify Profit Calculator](https://www.sellerscalc.com/shopify-profit-calculator): Shopify profit calculator: enter price, product cost, shipping and your Shopify Payments rate to see the real net profit and margin you keep per order.

### Unit Economics

- [Unit Economics calculators — category hub](https://www.sellerscalc.com/unit-economics): CAC, LTV, AOV and contribution — whether each customer earns more than they cost.
- [Customer Acquisition Cost (CAC) Calculator](https://www.sellerscalc.com/cac-calculator): CAC calculator: enter your total marketing and sales spend plus new customers won to get your customer acquisition cost and customers per $1,000 spent.
- [Customer Lifetime Value (LTV) Calculator](https://www.sellerscalc.com/ltv-calculator): customer lifetime value calculator: enter order value, purchase frequency, retention years and gross margin to get margin-based LTV and lifetime revenue.
- [LTV to CAC Ratio Calculator](https://www.sellerscalc.com/ltv-cac-ratio-calculator): LTV:CAC ratio calculator: enter customer lifetime value and acquisition cost to get the ratio and the share of lifetime value spent on acquiring each customer.
- [Average Order Value (AOV) Calculator](https://www.sellerscalc.com/aov-calculator): average order value calculator: enter total revenue and number of orders to get your AOV and how many orders make up each $1,000 of revenue.
- [Revenue Per Visitor (RPV) Calculator](https://www.sellerscalc.com/revenue-per-visitor-calculator): revenue per visitor calculator: enter total revenue and site visitors to get RPV and revenue per 1,000 visitors — the truest measure of traffic quality.
- [Contribution Margin Calculator](https://www.sellerscalc.com/contribution-margin-calculator): contribution margin calculator: enter selling price and variable costs per unit to get contribution margin in dollars and percent — what each sale adds.
- [CAC Payback Period Calculator](https://www.sellerscalc.com/cac-payback-calculator): CAC payback calculator: enter customer acquisition cost and monthly margin per customer to see how many months until each new customer turns cash-positive.
- [Churn Rate Calculator](https://www.sellerscalc.com/churn-rate-calculator): churn rate calculator: enter customers lost and customers at the start of the period to get your churn percentage and how many customers you retained.
- [Customer Retention Rate Calculator](https://www.sellerscalc.com/retention-rate-calculator): customer retention rate calculator: enter customers retained and your starting count to get retention percentage and the churn rate it implies.
- [Purchase Frequency Calculator](https://www.sellerscalc.com/purchase-frequency-calculator): purchase frequency calculator: enter total orders and unique customers for a period to see how often the average customer buys — a core input to LTV.
- [Customer Lifetime Orders Calculator](https://www.sellerscalc.com/customer-lifetime-orders-calculator): customer lifetime orders calculator: enter purchase frequency, years retained and average order value to project total lifetime orders and revenue per customer.
- [Refund Rate Calculator](https://www.sellerscalc.com/refund-rate-calculator): refund rate calculator: enter refunded orders, total orders and average order value to get your refund rate and the revenue those refunds hand back.

### Shipping & Landed Cost

- [Shipping & Landed Cost calculators — category hub](https://www.sellerscalc.com/shipping): Landed cost, duty and freight — the true per-unit cost of getting goods to the door.
- [Landed Cost Calculator](https://www.sellerscalc.com/landed-cost-calculator): landed cost calculator: enter product cost, freight per unit, duty rate and other charges to get the true per-unit cost of your imported inventory.
- [Import Duty Calculator](https://www.sellerscalc.com/import-duty-calculator): import duty calculator: enter the customs value of your shipment and its duty rate to see the duty owed and the total cost of the goods with duty included.
- [Customs VAT Calculator](https://www.sellerscalc.com/customs-vat-calculator): customs VAT calculator: enter goods value, freight, duty rate and VAT rate to see the import VAT owed and the total charges due at the border.
- [Dimensional Weight Calculator](https://www.sellerscalc.com/dimensional-weight-calculator): dimensional weight calculator: enter box dimensions in inches and your carrier divisor to get dim weight and the billable weight you will actually pay for.
- [Shipping Cost per Unit Calculator](https://www.sellerscalc.com/shipping-cost-per-unit-calculator): shipping cost per unit calculator: divide any freight bill by the units in the shipment to get the cost per unit and per 100 units for pricing and margin math.
- [Freight Cost Calculator](https://www.sellerscalc.com/freight-cost-calculator): freight cost calculator: enter shipment volume in CBM, the rate per CBM and fixed charges to see your total freight bill and the effective rate you really pay.
- [CBM Calculator](https://www.sellerscalc.com/cbm-calculator): CBM calculator: enter carton dimensions in centimeters and quantity to get total shipment volume plus how many cartons fit a 20ft or 40ft container.
- [Chargeable Weight Calculator](https://www.sellerscalc.com/chargeable-weight-calculator): chargeable weight calculator for air freight and couriers: compare actual weight with volumetric weight (cm ÷ 5,000) to see the kilograms you get billed for.
- [Container Utilization Calculator](https://www.sellerscalc.com/container-utilization-calculator): container utilization calculator: compare your cargo volume in CBM with container capacity to see the fill percentage and how much space ships empty.
- [Shipping Margin Calculator](https://www.sellerscalc.com/shipping-margin-calculator): shipping margin calculator: compare what you charge customers for shipping against your real label cost to see the profit or subsidy on every order.
- [Free Shipping Threshold Calculator](https://www.sellerscalc.com/free-shipping-threshold-calculator): shipping threshold calculator: use your average shipping cost, gross margin and AOV to set a minimum order value where free shipping pays for itself.
- [Total Import Cost Calculator](https://www.sellerscalc.com/total-import-cost-calculator): total import cost calculator: combine goods, freight, duty, VAT and broker fees into one landed total and a true per-unit cost for the whole shipment.

### Inventory

- [Inventory calculators — category hub](https://www.sellerscalc.com/inventory): Reorder points, EOQ and turnover — holding enough stock without drowning in it.
- [EOQ Calculator](https://www.sellerscalc.com/eoq-calculator): EOQ calculator: enter annual demand, cost per order, and holding cost per unit to get your economic order quantity and how many orders to place a year.
- [Reorder Point Calculator](https://www.sellerscalc.com/reorder-point-calculator): reorder point calculator: enter daily sales, supplier lead time, and safety stock to see the exact stock level at which to place your next order.
- [Safety Stock Calculator](https://www.sellerscalc.com/safety-stock-calculator): safety stock calculator using the max-minus-average method: enter best-case and typical daily sales and lead times to size your stockout buffer in units.
- [Inventory Turnover Calculator](https://www.sellerscalc.com/inventory-turnover-calculator): inventory turnover calculator: enter annual COGS and average inventory value to see how many times a year you sell through stock and days per turn.
- [Days of Inventory Calculator](https://www.sellerscalc.com/days-of-inventory-calculator): days of inventory (DIO) calculator: enter average inventory value and annual COGS to see how many days your current stock will last at today’s pace.
- [Sell-Through Rate Calculator](https://www.sellerscalc.com/sell-through-rate-calculator): sell-through rate calculator: enter units sold and units received for the period to get your sell-through percentage and how many units are left over.
- [Stock to Sales Ratio Calculator](https://www.sellerscalc.com/stock-to-sales-ratio-calculator): stock to sales ratio calculator: enter inventory value on hand and monthly sales to see how many months of stock you hold and whether you are over-bought.
- [Inventory Holding Cost Calculator](https://www.sellerscalc.com/inventory-holding-cost-calculator): inventory holding cost calculator: enter your inventory value and annual carrying rate to see what storing that stock really costs per year and month.
- [Dead Stock Cost Calculator](https://www.sellerscalc.com/dead-stock-cost-calculator): dead stock cost calculator: enter unsold units, unit cost, and holding rate to see the capital frozen in dead inventory and what keeping it costs yearly.
- [Fill Rate Calculator](https://www.sellerscalc.com/fill-rate-calculator): fill rate calculator: enter orders fulfilled from stock and total orders received to get your fill rate percentage and the backorders left waiting.
- [Weeks of Supply Calculator](https://www.sellerscalc.com/weeks-of-supply-calculator): weeks of supply calculator: enter units on hand and average weekly unit sales to see exactly how many weeks until this SKU sells out at the current pace.
- [Inventory Shrinkage Calculator](https://www.sellerscalc.com/inventory-shrinkage-calculator): inventory shrinkage calculator: enter recorded inventory value and the physically counted value to see your shrinkage rate and the dollars that vanished.

### Conversion & Email

- [Conversion & Email calculators — category hub](https://www.sellerscalc.com/conversion): Conversion rates, cart abandonment and email ROI — squeezing more from existing traffic.
- [Conversion Rate Calculator](https://www.sellerscalc.com/conversion-rate-calculator): e-commerce conversion rate calculator: enter visitors and conversions to get your CVR percentage and conversions per 1,000 visitors instantly.
- [Cart Abandonment Cost Calculator](https://www.sellerscalc.com/cart-abandonment-cost-calculator): cart abandonment calculator: enter carts started, checkout completion rate and average order value to see the monthly revenue abandoned carts cost you.
- [Email ROI Calculator](https://www.sellerscalc.com/email-roi-calculator): email marketing ROI calculator: enter campaign cost and attributed revenue to get your ROI percentage and the revenue earned for every dollar spent.
- [Email List Growth Calculator](https://www.sellerscalc.com/email-list-growth-calculator): email list growth calculator: enter subscribers gained, unsubscribes and current list size to get your monthly growth rate and net new subscribers.
- [Open Rate Calculator](https://www.sellerscalc.com/open-rate-calculator): email open rate calculator: enter unique opens and delivered emails to get your open rate percentage and opens per 1,000 delivered messages.
- [Email Click Rate Calculator](https://www.sellerscalc.com/email-click-rate-calculator): email click rate calculator: enter clicks, delivered emails and opens to get your click-through rate and click-to-open rate for any campaign.
- [A/B Test Significance Calculator](https://www.sellerscalc.com/ab-test-significance-calculator): A/B test significance calculator: enter visitors and conversions for both variants to get the lift, z-score and statistical confidence of your test.
- [Bounce Rate Revenue Loss Calculator](https://www.sellerscalc.com/bounce-rate-revenue-loss-calculator): bounce rate revenue calculator: enter monthly visitors, bounce rate, conversion rate and AOV to see how much revenue bounced visitors cost your store.
- [Popup Conversion Calculator](https://www.sellerscalc.com/popup-conversion-calculator): popup conversion rate calculator: enter popup views and email signups to get your popup conversion percentage and signups per 1,000 views.
- [Revenue per Email Calculator](https://www.sellerscalc.com/revenue-per-email-calculator): revenue per email calculator: enter campaign revenue and emails sent to get revenue per email and per 1,000 sent — the metric that values your list.

### Store Finance

- [Store Finance calculators — category hub](https://www.sellerscalc.com/finance): Cash cycles, runway and growth — the money mechanics behind the storefront.
- [Cash Conversion Cycle Calculator](https://www.sellerscalc.com/cash-conversion-cycle-calculator): cash conversion cycle calculator: enter days inventory outstanding, days sales outstanding, and days payable outstanding to get your CCC in days.
- [Working Capital Calculator](https://www.sellerscalc.com/working-capital-calculator): working capital calculator: enter current assets and current liabilities to get your working capital in dollars plus your current ratio instantly.
- [Runway Calculator](https://www.sellerscalc.com/runway-calculator): cash runway calculator: enter cash on hand and monthly net burn to see how many months your business can operate before the bank account hits zero.
- [Burn Rate Calculator](https://www.sellerscalc.com/burn-rate-calculator): burn rate calculator: enter net cash spent over a period and the number of months to get your average monthly burn rate and what it costs per day.
- [MRR Growth Calculator](https://www.sellerscalc.com/mrr-growth-calculator): MRR growth calculator: enter starting and ending monthly recurring revenue to get your month-over-month growth rate and the dollar MRR you added.
- [Revenue Growth Calculator](https://www.sellerscalc.com/revenue-growth-calculator): revenue growth calculator: enter revenue for a previous and current period to get the growth rate percentage and the absolute dollar change between them.
- [Net Profit Calculator](https://www.sellerscalc.com/net-profit-calculator): net profit calculator: enter revenue, cost of goods sold, and operating expenses to get your net profit in dollars and your net profit margin percentage.
- [Operating Margin Calculator](https://www.sellerscalc.com/operating-margin-calculator): operating margin calculator: enter operating income and revenue to get your operating margin percentage — the profitability of the core business itself.
- [ROI Calculator](https://www.sellerscalc.com/roi-calculator): ROI calculator: enter the cost of an investment and the total value returned to get ROI as a percentage and the multiple of your money it represents.
- [Break-even Revenue Calculator](https://www.sellerscalc.com/break-even-revenue-calculator): break-even revenue calculator: enter monthly fixed costs and gross margin percentage to get the monthly and daily revenue needed to cover your bills.

### Merchant tools (generators & checkers, all in-browser)

- [UTM Link Builder](https://www.sellerscalc.com/tools/utm-link-builder): UTM link builder for e-commerce campaigns. Build correctly encoded tracking URLs with source, medium and campaign values, then copy with one click.
- [Discount Code Generator](https://www.sellerscalc.com/tools/discount-code-generator): Generate hundreds of unique discount codes in your browser: custom prefix, length and safe character set, ready to paste into Shopify, WooCommerce or Amazon.
- [SKU Generator](https://www.sellerscalc.com/tools/sku-generator): SKU generator: build a consistent SKU scheme (brand, category, variant, sequence) and generate the whole list at once, ready for your catalog spreadsheet.
- [Product URL Slug Generator](https://www.sellerscalc.com/tools/product-slug-generator): Turn product names into clean, SEO-safe URL slugs and Shopify handles in bulk: lowercase, hyphenated, accents stripped, junk words removed. Free, no signup.
- [Marketplace Character Counter](https://www.sellerscalc.com/tools/marketplace-character-counter): Live character counter checked against real marketplace limits: Amazon and Etsy titles, Google title and meta description, eBay and Shopify fields. Free tool.
- [Barcode Generator](https://www.sellerscalc.com/tools/barcode-generator): barcode generator: turn any SKU or product number into a scannable Code 128 or EAN-13 barcode, then download it as SVG or PNG. Runs in your browser.

- [All calculators](https://www.sellerscalc.com/): the homepage lists every calculator and tool by category.

## Core formulas

- contribution margin = price − (COGS + shipping + fees + fulfillment + other)
- gross margin fraction = contribution margin ÷ price
- break-even ROAS = price ÷ contribution margin = 1 ÷ gross margin fraction
- break-even ACOS = gross margin fraction, as a percentage
- target ROAS = price ÷ (contribution margin − target margin % × price)

## Notes for agents

- Calculator pages expose a WebMCP tool (`calculate_break_even_roas`) via
  navigator.modelContext where the browser supports it.
- All results are estimates: per-order variable costs only, excluding
  returns, overhead and taxes.