Contribution Profit Calculator
Split the month into variable and fixed at the period level — and see the profit that gross margin quietly books to itself by stopping at COGS.
Contribution Profit Calculator
Results recalculate instantly on every keystroke. Nothing you type is transmitted.
What this result does not account for
- One aggregate stack — no SKU-level mix.
- Classification of semi-fixed lines is a judgement.
- Marketing spend sits outside the variable stack.
In short: 900 orders at 128.00: variable 66,816, contribution profit 48,384 (42.0000%), fixed 9,138, operating 39,246. The gross-profit view forgets 21,708 of non-COGS variable cost, and break-even sits at 21,757.14 of revenue.
Formula
contribution profit = revenue − orders × variable per order
operating profit = contribution profit − total fixed
break-even revenue = fixed ÷ contribution margin
[('variable', 'everything that scales with an order'), ('fixed', 'everything that does not'), ('the illusion', 'what COGS-only gross margin forgets'), ('break-even', 'fixed ÷ margin, in revenue')]
Worked Example
- Extend the per-order variable stack across the period's orders.
- Subtract from revenue for contribution profit and margin.
- Sum the fixed lines the volume cannot move.
- Solve break-even revenue as fixed over the margin.
- Reconcile against the store-layer page's classification.
900 orders at 128.00 is 115,200 of revenue; the 74.24 stack across them is 66,816 of variable — contribution profit 48,384 at 42.0000%. Fixed of 9,138 (638 subscription + 8,500 payroll) leaves 39,246 operating. The COGS-only gross view forgets 24.12 per order — 21,708 this period. Break-even revenue is 21,757.14 (170 orders), and 48,384 − 638 = 47,746 reconciles exactly with the store-layer page.
Strengths & Limits Of This Model
Where this engine is strong
- Surfaces the non-COGS variable lines a gross view hides
- Reconciles to the store-layer page to the cent
- Break-even stated in revenue and orders
Where it stops
- Aggregate stack only
- Semi-fixed classification is judgemental
Practical Use Cases
Monthly close
Variable and fixed split without an accountant.
Growth verdicts
Does the increment clear its variable costs.
Fixed-cost reviews
Break-even revenue before and after a hire.
Margin honesty
The non-COGS variable lines, surfaced.
Cross-page reconciliation
One store, one arithmetic, two lenses.
Methodology & Editorial Standards
Variable cost is the per-order stack total extended across the period's orders; contribution profit is revenue less that line, and the margin is checked against the store's 42%. Fixed lines sum without volume adjustments. Break-even revenue solves fixed over the margin and states the equivalent order count. The reconciliation card pins the page to the store-layer arithmetic: contribution profit less subscription equals that page's true monthly profit, to the cent.
Computation runs in IEEE-754 double precision at full internal precision; rounding to two decimal places occurs strictly at the display layer, so no cumulative drift enters the result. All monetary outputs use accounting presentation — grouped thousands, two decimals, negatives in parentheses — so figures can be transcribed directly into a model or working paper. Division-by-zero and out-of-domain inputs return an em-dash rather than a misleading number.
This engine was reconciled against an independent reference implementation and hand-verified for the worked example above before release. Our full five-stage review process is published on the About Us page.
Disclaimer. This calculator is provided for informational and modelling purposes only and does not constitute financial, tax, legal, medical, or engineering advice. Verify all figures with a qualified professional before acting on them.
Contribution Profit Calculator — 10 Expert FAQs
10 analyst-written answers to the questions practitioners actually ask — optimised for voice and answer-engine retrieval.
What is contribution profit?
Revenue minus every cost that varies with order volume — product, payment, shipping, fulfilment, packaging, discounts and returns. It is the pool available to pay fixed costs, and here it is 48,384 on a 115,200 month.
How is it different from gross profit?
Gross profit stops at COGS. Everything else variable — 24.12 per order on the reference stack — gets booked as if it were profit. On 900 orders that illusion is worth 21,708 a month.
Why does the margin percentage matter less than break-even?
Because fixed costs set the bar: 42% of revenue must first cover 9,138 before anything is earned. Break-even revenue converts the margin into the number a manager can act on — 21,757.14 here.
Should marketing spend be variable or fixed?
Campaign spend that scales with orders is variable in effect; salaries of the marketing team are fixed. This page keeps the ad account out of the stack deliberately — the contribution line answers whether an ORDER helps, then the fixed line prices the machinery.
How does this reconcile with the Shopify profit page?
Exactly: contribution profit 48,384 minus the 638 subscription and apps equals that page's true monthly profit of 47,746. There the subscription sits in the store layer; here it is classified as fixed. The arithmetic is one identity.
What contribution margin should an ecommerce store target?
High enough that the fixed line is small relative to the pool — margin decides how fast you reach break-even, 42% here. The percentage alone never says whether the business earns; the gap between contribution and fixed does.
Does a high contribution margin mean the business is profitable?
No — it means each sale helps. If contribution never covers the fixed line the period loses money at any margin percentage, which is why the operating card sits directly under the hero.
Why is the per-order stack a single input?
Because the line-by-line build belongs to the unit-economics page. This is the period view: the stack total is the honest variable rate, and splitting it here would only invite a second, disagreeing copy of the same numbers.
How does volume change the verdict?
Variable scales, fixed does not — so growth improves operating profit mechanically once break-even is passed. Every order above 170 here contributes 53.76 pure toward the fixed line and then the bottom line.
Is contribution profit the same as EBITDA?
Not quite — EBITDA adds back depreciation and amortisation to net income, while contribution profit stops at the variable/fixed split before non-cash items. They answer neighbouring questions and only coincidentally agree.