Life Calculator

Break Even Calculator

The break-even point is the sales level at which a business stops losing money. Every unit after it contributes to profit.

Last reviewed: Written and checked by the Life Calculator editorial team

Rent, salaries, insurance — costs that do not change with volume.

Materials, packaging, per-unit shipping.

units

Optional — used for the margin of safety.

The calculation

Contribution margin = price − variable cost per unit Break-even units = fixed costs ÷ contribution margin Break-even revenue = break-even units × price

The contribution margin is the key figure: it is what each sale contributes towards covering fixed costs once its own direct costs are paid. At £45 a unit with £18 of variable cost, each sale contributes £27. With £5,000 of fixed costs, you need 186 units to cover them.

Round up, always. 185.2 units means 186, because you cannot sell a fifth of a unit and 185 leaves you short.

Sorting fixed from variable

Getting this split right matters more than the arithmetic:

FixedVariable
Rent and business ratesRaw materials
Salaried staffHourly or piece-rate labour
InsurancePackaging
Software subscriptionsPayment processing fees
AccountancyShipping per order
Equipment depreciationSales commission

Two complications in practice. Semi-variable costs — a phone contract with a fixed line rental plus usage charges — need splitting into their two parts. And step costs are fixed only within a range: one delivery van handles 500 orders a month, and order 501 requires a second van. Break-even analysis assumes linearity, so recalculate at each step.

Margin of safety and what to do with it

Margin of safety = (expected sales − break-even) ÷ expected sales × 100

This is how far sales can fall before you start losing money. At 300 units expected against a 186-unit break-even, the margin is 38 % — sales could drop by more than a third before trouble. Below about 20 %, the business is fragile to a bad quarter.

There are only four levers on the break-even point, and it is worth knowing their relative power:

  1. Raise the price. Usually the strongest lever, because the whole increase goes to contribution. A 10 % price rise here cuts break-even by 14 %.
  2. Cut variable costs. Better supplier terms, less waste, cheaper packaging.
  3. Cut fixed costs. Directly proportional: 10 % less fixed cost means 10 % fewer units needed.
  4. Change the mix towards higher-margin products.

Frequently asked questions

What if I sell several different products?

Use a weighted average contribution margin based on your actual sales mix, then divide fixed costs by that. The result is valid only while the mix holds — if customers shift towards your lower-margin lines, break-even rises even though total units do not change.

Should my own salary be a fixed cost?

Yes, if you need to be paid. Many small businesses calculate break-even excluding the owner's income and then discover the business cannot actually support them. Include a realistic salary in fixed costs from the start.

Does break-even include tax?

No. It is a pre-tax measure: at break-even, profit is zero, so there is nothing to tax. If you are targeting a specific after-tax profit, gross it up first by dividing by (1 − tax rate) before adding it to fixed costs.