GMROI Calculator

A GMROI above 1.0 means inventory returns more margin than it costs to hold in stock, but 1.0 barely covers carrying costs. Most healthy retailers target 2.0–3.0 overall; fast-turning categories like consumables can exceed 4.0, while slow luxury goods may run lower and compensate with margin. Compare products against your own portfolio average — the gap between your best and worst GMROI is where the buying budget should move.

Take your inventory value at cost (not retail) at regular intervals and average them: (beginning + ending) ÷ 2 works for a rough annual figure, but a monthly average of 12–13 snapshots is far more honest for seasonal businesses. Using a single year-end count understates average inventory for anyone who stocks up before peak season, which inflates GMROI.

Margin ignores time and capital. A 60% margin item that turns once a year earns 0.6 GMROI-style dollars per invested dollar; a 30% margin item turning six times earns roughly 1.8. GMROI multiplies margin by velocity, so it ranks products by what they actually pay you per dollar tied up — which is the real constraint for a cash-limited store.

Attack either side of the fraction. Raise margin dollars: increase prices where demand allows, cut landed costs, drop chronic markdown items. Or shrink the inventory base: order smaller quantities more often, clear dead stock even at a loss (it frees denominator dollars), and reallocate open-to-buy toward the products this calculator scores highest.