E-Commerce Unit Economics Calculator
Most e-commerce plans fail on two numbers: contribution per order, and how many orders a month cover fixed costs. Revenue targets get set without either, which is why “we hit the target and still lost money” is such a common sentence.
Works per order. Currency doesn't matter — keep every field in one.
Contribution per order
369
49% of AOV. After acquisition, the first order leaves 189.
Customer economics
Break-even
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How it's calculated
Contribution is what's left of the order value after every variable cost: goods, packaging, the shipping you absorb, payment fees and a returns allowance. Fixed costs are not in here — they come next.
Returns are costed as two-way shipping plus lost packaging. Leaving this out is what disguises a break-even product as a profitable one.
CAC payback is acquisition cost divided by contribution: how many orders it takes to recover it. If that exceeds your annual order rate, the model loses money per customer — faster the more you grow.
Monthly break-even orders is fixed costs divided by contribution. It's a far more useful target than revenue: “340 orders a month” is both more concrete and more honest than a revenue figure.
What people most often forget
- Free shipping is a marketing cost, not a logistics one. A basket threshold usually lifts both margin and order value better than removing it outright.
- CAC isn't only ad spend. Agency fees, content, influencers and discount codes all acquire customers too.
- Repeat purchase must be measured, not hoped for. Losing money on the first order is a legitimate strategy only if you actually track returning customers.
- Put your own salary in the fixed costs. A founder working unpaid is a subsidy, not a business model, and it hides whether the thing actually stands up.
- Raising AOV is usually easier than raising conversion. Bundles, multipacks and shipping thresholds lift contribution without needing more traffic.
Scope, sources and freshness
A scenario calculator, not a replacement for your accounts. Tax, depreciation, inventory write-downs and seasonality are out of scope. Every rate and cost is your own input — no industry averages are assumed. Keep all fields in one currency.
Sources last reviewed: 16 August 2026
Frequently asked
Is contribution the same as gross profit?
No. Gross profit usually deducts only COGS; contribution deducts every variable cost tied to the order — shipping, payment fees, packaging and returns. Contribution is the number you decide with.
What LTV/CAC ratio should I target?
Three or above is the common target; below that, funding overheads and growth gets hard. But the ratio alone isn't enough — how fast you repay CAC matters just as much, because cash is about timing.
I don't know my return rate — what should I enter?
Enter a pessimistic estimate and run two scenarios. Apparel and footwear run several times higher than most categories, and assuming high is far cheaper than assuming low.
What counts as a fixed cost?
Everything you pay with zero sales: rent, salaries, software, warehousing, accounting. Ads count as variable because you can cut them — though cutting them cuts sales, which is why they sit on the CAC side.
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