📦 Small business planning tool

Break-Even Calculator (UK)

Estimate how many units you need to sell to cover your fixed costs, how much revenue gets you to break-even, and what sales volume is needed to hit a target profit. Useful for ecommerce sellers, side hustles, product launches, market stalls and service businesses that price work by the job.

Enter your costs and selling price

Break-even uses a simple contribution-margin formula: (fixed costs) ÷ (selling price minus variable cost). This is a planning calculator, not bookkeeping or tax advice. It does not model discounts, refunds, payment-processor tiers, ad spend spikes or seasonal stock write-downs unless you include them in your inputs.

How to use a break-even calculator properly

A break-even check helps answer one practical question: when does this stop losing money? Start with your monthly fixed costs such as rent, software, insurance, phone, subscriptions, storage, or retained freelance help. Then add the direct cost attached to each sale, like stock, packaging, marketplace fees, card fees or per-job materials.

The important number is contribution per unit. That is the amount left from each sale after the variable cost has been taken off. Contribution is what pays your fixed costs first, and only after that starts creating profit. If contribution is thin, you may need a higher price, lower variable cost, or a different product mix.

For UK sellers, one common mistake is mixing VAT-inclusive and VAT-exclusive numbers. If you are VAT registered and the customer price includes VAT, the VAT slice is not really yours to keep. This calculator lets you treat your selling price as VAT inclusive so the net price is used for the contribution maths.

What the results mean

  • Break-even units: the minimum whole number of sales needed to cover fixed costs.
  • Break-even revenue: the sales income tied to that unit volume.
  • Contribution margin ratio: the share of each pound of sales available to cover fixed costs and profit.
  • Target-profit units: the units needed to cover fixed costs and still hit your chosen profit goal.
  • Units above break-even: your buffer at the expected sales volume you entered.

If your buffer is tiny, even a small dip in conversion, higher postage, or a few returns could push the month negative. That usually means the pricing is fragile rather than safely profitable.

Good uses for this page

  • Launching a new product and testing whether the price is realistic.
  • Checking whether ad spend or fulfilment changes break the economics.
  • Comparing two suppliers with different unit costs.
  • Working out how many client jobs you need each month to cover overhead.
  • Setting sensible minimum order values or bundle offers.

For ecommerce, break-even works best when you model your real landed cost rather than just product cost. Include the boring stuff: labels, void fill, inserts, picking time, promoted listings, card fees and return leakage.

Quick example

Suppose your fixed monthly costs are £1,200. You sell a product at £24.99 and the variable cost per unit is £9.25. That leaves about £15.74 contribution per sale. You would need roughly 77 units to cover fixed costs. If you expect to sell 150 units, your projected monthly profit is about £1,161 before corporation tax or income tax.

That does not guarantee a good business, but it does tell you the unit economics are at least pointing the right way. If break-even needed 240 units and you usually sell 70, you would know the model needs work before you commit more time or cash.