Canonical formula calculator
CONTRIBUTION MARGIN
What each sale contributes to fixed costs and profit, in percent and dollars — the per-unit version of gross margin.
What you charge for one unit of the product.
The cost that scales directly with each unit sold — materials, payment processing, fulfillment.
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What this tells you
Contribution margin tells you what each individual sale contributes after variable costs — both as a percent of price and as dollars per unit. Above 50% is healthy for most products. The percent matters for comparison across products and price points; the per-unit dollar matters for thinking about volume and break-even. This calculator shows both.
When to use it
Calculate contribution margin per product when setting prices, evaluating discounts, or deciding which products to push. A low-percent product can still be your best seller if volume is high and the per-unit dollar is meaningful. A high-percent product can still be a bad bet if no one buys it. Both numbers are required for real pricing decisions.
What it doesn’t tell you
Contribution margin treats variable cost as a single number. In reality, variable costs scale differently — some are perfectly linear with units sold, some have step functions (a new warehouse at 10K units, a new server at 100K users). Use contribution margin for marginal decisions; use full cost analysis for structural ones.
Track it, don’t just calc it
A calculator gives you today’s number. Reckon turns it into a goal you can watch: declare it as a number and a date, log progress by hand, and get a deterministic verdict with a real arrival date. No AI, no guessing — the same input always gives the same answer.