Build a break even calculator: costs and price in, units and a chart out
A break-even calculator answers one question before you commit to a price: how many do I have to sell before I stop losing money? Fixed costs, the cost of each unit and the price go in; the number of units, the revenue at that point and a chart of profit come out. Anticode can build one as a small app for your own planning or as a tool on a site for founders.
Three numbers and one formula
Break-even units = fixed costs ÷ (price − variable cost per unit). The bit in brackets is the contribution margin: what each sale contributes towards the fixed costs once its own costs are paid. Everything else in a break-even point calculator is presentation and edge cases.
- Fixed costs
- Costs that don't change with volume over the period: rent, salaries, software, insurance. Ask for the period too (per month or per year), because the answer is units per that period.
- Variable cost per unit
- Materials, packaging, payment processing, delivery, platform fees, anything that scales with each sale.
- Price
- Before or after sales tax, decided once and stated in the interface. Mixing the two is the most common error.
If price is at or below variable cost, there is no break-even point: every sale loses money. The calculator should say exactly that rather than showing a negative or infinite number of units.
Margin and markup, kept apart
A profit margin calculator and a markup calculator answer different questions, and confusing them leads to under-pricing. Margin is profit as a share of the price; markup is profit as a share of the cost. A product costing 6 and selling for 10 has a 40% margin and a 67% markup. Show both, labelled, and let the user type a target margin to get the price that achieves it.
Scenarios are where it earns its keep
One break-even figure is a fact; three side by side are a decision. Ask for scenario columns: the current price, a higher price, and a lower price with an expected volume increase. Each column shows units to break even, revenue at break-even, margin, and profit at the expected volume.
The chart is the classic one: a flat fixed-cost line, a total-cost line rising from it, and a revenue line from zero. Where revenue crosses total cost is the break-even point, and the shaded gap beyond it is profit. A slider for price that redraws the chart live shows founders how sensitive the result is in a way a table can't.
- Multiple products. A weighted average contribution margin by expected sales mix, if you sell more than one thing.
- Target profit. Units needed to reach a chosen profit, not just zero.
- Time to break even. Divide units by expected monthly sales to get months, useful when pitching.
- Saved scenarios. Ask for them to be remembered in the browser so a founder can come back to them.
Describing it to Anticode
"A break even calculator for people starting a small product business. Inputs: monthly fixed costs (an itemised list that totals itself), variable cost per unit (also itemised), and price. Show break-even units per month, revenue at that point, margin and markup. Three scenario columns with a price slider each, and a cost-volume-profit chart. Plain, technical design with tabular figures."
For a service business the unit might be an hour or a booking rather than a product; say so and the labels follow. Related tools on the same site might be a freelance rate calculator, an ROI calculator or a SaaS pricing calculator. If it's for your own pricing decision rather than a public tool, you can keep the published link to yourself.
Limits
- It assumes straight lines. Real costs step up (a second machine, a new hire) and prices get discounted. The model is a first approximation; say so on screen.
- No live data. The app can't fetch supplier prices, exchange rates or your sales figures; they're typed in.
- No accounting. It isn't connected to bookkeeping software and doesn't replace a cash-flow forecast. Break-even ignores timing: you can be above break-even and still run out of cash.
- Not shared. A co-founder opening the link sees their own blank copy, not your saved scenarios.
Questions people ask
Should break-even include my own salary?
If you need to pay yourself to keep going, yes. Put a modest salary in fixed costs; otherwise the break-even point flatters the business.
Does the break even calculator handle subscriptions?
Use one month of a subscription as the unit and monthly costs as fixed costs. For churn and lifetime value you'd want a different model.
Can I put it on my business website for clients?
Yes. It publishes like any Anticode site, and anything visitors type stays in their own browser.