Break-Even Calculator
- No invented stats
- Written for UK readers
- Published 24 September 2026
Break-even is the point where the money coming in has covered everything going out, and the next sale starts making a profit. This calculator works out how many units you need to sell to get there, what that is worth in revenue, and how many more you need for a target profit on top. It runs entirely in your browser — nothing you enter is sent anywhere.
How this works
Split your costs in two. Fixed costs stay roughly the same however much you sell — rent, salaries, software, insurance. Variable costs happen per unit sold — materials, delivery, payment fees, the cost of the licence you resell.
Take the variable cost off the selling price and what is left is the contribution: the amount each sale puts towards the fixed costs. Divide the fixed costs by the contribution per unit and you have the number of units you need to sell:
fixed costs ÷ (price per unit − variable cost per unit) = break-even units
The calculator rounds that figure up, because you cannot sell four fifths of a unit and be covered. For a target profit, add the profit you want to the fixed costs before dividing — the maths is identical, you are just treating the profit as another cost to cover.
Use a period that matches your fixed costs. If you enter a month of fixed costs, the answer is units per month.
A worked example
A small firm has £30,000 of fixed costs a quarter. It sells one product at £250, and each one costs £100 in materials, shipping and card fees.
- Contribution per unit: £250 − £100 = £150
- Break-even units: £30,000 ÷ £150 = 200 units a quarter
- Break-even revenue: 200 × £250 = £50,000
- Contribution margin: £150 ÷ £250 = 60%
Unit 201 is the first one that makes any profit, and it makes £150. If the firm also wants £15,000 of profit in the quarter, the sum becomes (£30,000 + £15,000) ÷ £150 = 300 units, or £75,000 of revenue.
The contribution margin is the quick sanity check on any change. At a 60% contribution margin, every £1,000 of extra fixed cost needs £1,667 of extra revenue to cover it, and a £10 price cut drops the contribution to £140, which pushes break-even from 200 units to 215.
What this doesn't account for
- Costs that are only sort of fixed. Hire a second person or add a warehouse and your fixed costs step up. Break-even from that point is a new calculation.
- More than one product. With a mixed range, the answer depends on which products sell. Run it per product, or use an average contribution weighted by your actual sales mix.
- Timing. Break-even is a profit measure, not a cash measure. You can be past break-even on paper and still short of cash if customers pay in sixty days.
- VAT. Use figures excluding VAT. If you are working from gross numbers, our UK VAT calculator will strip it out properly.
If you are not sure what margin you are working on, the profit margin and markup calculator works it out from cost and price. And before you agree to a price cut, the discount impact calculator shows how far it pushes your break-even point out.
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