SellersCalc

Finance math

ROI Calculator

One percentage that makes an ad campaign, a bulk inventory buy, and a new tool comparable.

ROI = (return − cost) ÷ cost × 100. Put $10,000 into inventory that sells through for $14,000 and the gain is $4,000 — a 40% ROI, or 1.4× your money back. ROI deliberately ignores time, so annualize before comparing options: 40% earned in three months can be redeployed four times a year and beats a 60% return that takes eighteen months. Count the return net of the costs of realizing it — fees, shipping, ad spend — or the percentage flatters. Enter cost and return to get the ROI and the multiple.

ROI Calculator — your numbers

Return on investment

40.0%

Return multiple

1.40×

Estimate only. Results reflect exactly the numbers you enter — verify against your own accounting before making pricing decisions.

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Worked examples

Bulk inventory buy

Investment cost $10,000.00
Total value returned $14,000.00
Return on investment 40.0%
Return multiple 1.40×

40% ROI — strong if it sells through in a quarter, mediocre if it takes a year.

A campaign that worked

Investment cost $5,000.00
Total value returned $20,000.00
Return on investment 300.0%
Return multiple 4.00×

300% ROI and 4× the money — the kind of result worth scaling until it degrades.

Frequently asked questions

What is the difference between ROI and ROAS?

ROAS is revenue ÷ ad spend and ignores product costs entirely; ROI measures actual profit against the investment. A 3× ROAS on a product with a 30% gross margin is $0.90 of margin per ad dollar — a negative 10% ROI. Ad platforms report ROAS because it flatters; run the ROI math before scaling any campaign.

How do I annualize an ROI to compare investments fairly?

Compound by the number of times the period fits in a year: annualized ROI = (1 + ROI)^(12 ÷ months) − 1. A 40% return in three months annualizes to (1.4)^4 − 1 ≈ 284%, while 40% over a year is just 40%. Fast-turning inventory with modest per-cycle ROI often beats slow investments with impressive headline percentages.

Which costs belong in the investment cost figure?

Every dollar the opportunity consumed: purchase price, inbound freight and duty, storage, payment and marketplace fees, and the ad spend used to sell it. The most commonly omitted cost is your own time — price it at a realistic hourly rate for projects that eat weeks, or the ROI comparison against passive alternatives is rigged.

What counts as a good ROI for merchant decisions?

Anchor on the alternatives. Index funds return roughly 7–10% annually, so a business investment carrying real risk and effort should clear well above that — many operators want 25–50%+ annualized before committing capital. Repeatability matters more than one great number: a 30% ROI you can run monthly outclasses a one-off 100%.

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Part of the Store Finance collection.