Break-Even Calculator

A break-even calculator tells you the level of sales or revenue at which a business or project covers all its costs, earning neither a profit nor a loss. It is used by entrepreneurs evaluating business ideas, managers reviewing pricing decisions, and investors assessing the viability of a new product or venture.

How to Use the Break-Even Calculator

1. Enter your fixed costs: the monthly or annual expenses that stay constant regardless of sales volume (rent, salaries, insurance, software subscriptions).
2. Enter the selling price per unit.
3. Enter the variable cost per unit: direct costs that increase with each unit sold (materials, packaging, payment processing fees, direct labour).
4. Click calculate to see the break-even point in units and in revenue.
5. Adjust price or costs to see how changes affect the break-even threshold.

The Formula

Break-Even Units = Fixed Costs / (Selling Price - Variable Cost Per Unit)

The denominator (Selling Price - Variable Cost Per Unit) is called the Contribution Margin Per Unit: the amount each unit sold contributes towards covering fixed costs.

Break-Even Revenue = Fixed Costs / Contribution Margin Ratio

Where Contribution Margin Ratio = (Selling Price - Variable Cost Per Unit) / Selling Price

Real-World Example

A small business sells handmade candles online. Fixed monthly costs: £1,200 (premises £600, staff £400, software £200). Selling price: £18 per candle. Variable cost per candle: £6 (materials, packaging, postage).

• Contribution margin per unit: £18 - £6 = £12
• Break-even units: £1,200 / £12 = 100 candles per month
• Break-even revenue: 100 x £18 = £1,800 per month

At 100 candles, the business covers all costs exactly. At 150 candles, it makes a profit of (150 - 100) x £12 = £600 per month. If the owner raises the price to £20, break-even falls to 86 candles, showing how a small price increase has a significant impact on profitability.

Using Break-Even Analysis to Make Decisions

Break-even analysis is most valuable when comparing scenarios: what happens to break-even if you hire a member of staff? If you invest in equipment that reduces variable costs? If you cut price to increase volume? The calculator makes these trade-offs visible. A business should aim to exceed break-even as early as possible; the time from launch to break-even is a key indicator of how much capital is needed to sustain the business. If break-even requires volumes that seem unrealistic given the target market, the pricing or cost structure needs rethinking before launch. It is also worth calculating the margin of safety: the percentage by which actual sales can fall before you hit break-even, which tells you how exposed the business is to a revenue dip.

Frequently Asked Questions

What is the contribution margin and why does it matter? The contribution margin is the selling price minus variable cost per unit. It represents the amount each sale contributes towards covering fixed costs and generating profit. A higher contribution margin means fewer units need to be sold to break even. Businesses with high fixed costs and low variable costs (software, media) typically have high contribution margins and relatively low break-even points relative to potential scale.

How does break-even analysis help with pricing decisions? If you reduce your price, the contribution margin falls and break-even units increase. If you raise your price, the contribution margin rises and break-even falls, but demand may also fall. Break-even analysis lets you model these trade-offs quantitatively, so pricing decisions are grounded in data rather than guesswork. The optimal price is usually the one that maximises total contribution margin, which requires an estimate of price elasticity of demand.

What are fixed costs and what are variable costs? Fixed costs remain constant regardless of sales volume: rent, salaries, loan repayments, insurance, and annual subscriptions. Variable costs change with output: materials, transaction fees, direct packaging, and delivery costs. Some costs are semi-variable (utilities, for example, have a fixed component and a usage component). For break-even analysis, semi-variable costs are usually split into their fixed and variable elements.

Can break-even analysis be used for service businesses? Yes. For service businesses, replace "units" with billable hours, projects, or client contracts. The variable cost is the direct cost per hour or project (staff time, subcontractors, travel), and the selling price is the fee charged. Break-even in hours tells you how many billable hours per month are needed to cover all costs.

Break-even across a price and cost grid

The single example above moves one input at a time. A grid shows how the price and the variable cost interact, with fixed costs held at £1,200 throughout.

Each cell is £1,200 divided by the contribution margin, rounded up to the next whole unit because a fraction of a candle cannot be sold. The grid makes a trade-off visible: a £2 rise in price and a £2 cut in variable cost do identical work here, because both add £2 to the margin. The diagonal from 134 units at the top left to 86 at the bottom right is every combination that lands on the same threshold.

What a change in fixed costs does

Fixed costs move the whole threshold rather than tilting it.

Hiring one person at £400 a month lifts the threshold from 100 candles to 134. The extra 34 candles exist to pay for the hire and contribute nothing to profit until they are sold, so the hire has to earn more than £400 a month in value before the business returns to its previous position. Reading the table before a commitment gives the size of that obligation in units, which is easier to test against a realistic sales forecast than a number in pounds.

Profit, loss and the margin of safety

The break-even point divides the volume line into two halves. Everything below it is a loss, and everything above it earns at the contribution margin rate.

The margin of safety is the room between where sales actually sit and the break-even line, expressed as a share of actual sales. At 150 candles it is 33.3%, which means sales can fall by 50 units before the business stops covering its costs. That figure answers a question the break-even point alone cannot: how much cushion exists if the market turns.

A service business worked through

The formula does not need physical units. A consultancy bills £90 an hour, pays £35 an hour in direct cost and carries £4,000 a month of fixed costs.

Every billed hour carries £55 towards the £4,000. Non-billable time does not appear in the calculation, which is the trap with service businesses: the working week holds meetings, admin and travel that no client pays for, so 73 billed hours means more than 73 hours at the desk. At 100 billed hours the margin of safety is 27.3%.

Where the arithmetic stops holding

Three assumptions carry the arithmetic: the selling price and the unit variable cost are held constant at every volume, fixed costs are held constant across the range, and every unit made is assumed to sell. It covers one product at one price.

Three situations break those assumptions. A volume discount schedule means the price falls as units rise, so the contribution margin is not one number. A mix of products needs a weighted average contribution margin, with each product weighted by its share of sales. A step in fixed costs, such as a second shift or another machine, creates a second break-even point above the step rather than one line across the whole range. Round the unit count up in every case, because the threshold is the first whole unit at which costs are covered.

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