Last updated: 2026-05-13

The break-even point

The break-even point is the sales volume at which total revenue exactly equals total costs — no profit, no loss. Every unit sold beyond that point generates pure profit at the contribution margin rate; every unit short of it deepens an operating loss. The calculation takes three inputs — fixed costs, selling price, and variable cost per unit — and returns the break-even quantity and the break-even revenue.

Fixed costs vs. variable costs

The formula rests on a clean split between two cost categories.

Fixed costs (FC) stay constant regardless of output volume. Rent, equipment leases, salaried payroll, annual insurance premiums, and software subscriptions are all fixed: they are owed whether the business sells one unit or ten thousand. The total is measured over a chosen period — monthly, quarterly, or annual — with the selling price and variable cost stated on the same period basis.

Variable costs (VC) scale directly with each unit produced or delivered. Raw materials, packaging, credit-card processing fees, and per-project freelance labor are all variable: producing twice as many units costs roughly twice as much on these inputs.

A cost that has both a fixed base charge and a usage component — utilities, for example — can be split: the base fee counts as a fixed cost and the usage portion as variable cost per unit.

Contribution margin

Subtracting variable cost from price gives the contribution margin (CM) — the amount each sale contributes toward covering fixed costs and, once those are covered, toward profit.

A bakery selling a loaf for 8.00 (in any currency) with 3.20 in variable costs (flour, packaging, payment processing fee) has a CM of 4.80. Every loaf sold adds 4.80 to the pool that pays rent, insurance, and salaries.

The contribution margin ratio (CMR) expresses the same idea as a percentage of revenue:

For the bakery: CMR = 4.80 / 8.00 = 60%. Sixty percent of every unit's revenue remains after variable costs are paid.

Computing the break-even point

With the contribution margin known, the break-even quantity follows directly:

If the bakery's monthly fixed costs are 9,600, break-even is 9,600 / 4.80 = 2,000 loaves. The 2,001st loaf sold in the month is pure profit.

Across multiple products at different price points, tracking revenue is often more practical than tracking units. The break-even revenue formula uses the CMR:

Same bakery: 9,600 / 0.60 = 16,000 in monthly revenue. At that figure the business covers all costs; anything above it flows to the bottom line.

Sensitivity to the inputs

Break-even analysis is most useful as a "what if" tool ahead of a decision, because each input moves the break-even point in a predictable way.

• Fixed costs rise 10% (a rent increase, an added part-time employee): break-even units rise by exactly 10%. The relationship is linear, which makes it easy to model.
• Variable costs increase (a supplier raises material prices): the contribution margin shrinks, so more units are needed to cover the same fixed base.
• Price increases: the contribution margin widens and break-even falls. Price increases carry demand risk, but their leverage on the break-even point is often larger than an equivalent cut in fixed costs.
• Price cuts to compete: break-even volume rises, possibly sharply. Whether the higher volume is realistically achievable is worth checking before the cut is committed to.

Practical context by business type

Product businesses face the starkest version of this analysis because every unit has measurable material and labor cost. Consumer goods startups often discover that a seemingly healthy gross margin collapses when fixed overhead is included — break-even analysis forces that honest accounting early.

SaaS and subscription businesses have very low variable cost per additional customer (marginal cost close to zero), so the CMR is high and fixed costs are the main driver of break-even. The relevant break-even metric is monthly recurring revenue (MRR) needed to cover infrastructure, headcount, and other fixed spend.

Service businesses — consulting, legal, healthcare, tutoring — typically bill per engagement or hour (the "price per unit"). Variable costs are low (minimal materials), which pushes the CMR high. Break-even is driven by billable hours or client count, and capacity — hours in a workday, number of clients a practitioner can serve — sets a hard ceiling on volume.

Retail involves many SKUs at different margins. The break-even point is best computed for each major product category separately, then weighted by sales mix to give a blended picture.

Assumptions and limits

This calculation models a single product at a constant price and constant variable cost — the simplest, most widely applicable break-even framework.

• Multiple products: a sales-mix-weighted average CMR applies. A shift in mix toward lower-margin products raises break-even even when individual prices do not change.
• Taxes not included: this is a pre-tax model. After-tax break-even requires scaling fixed costs up by the effective tax rate, or running the calculation on after-tax contribution margins.
• Capacity constraints: break-even assumes the required volume can be produced and sold. When that volume exceeds physical or staffing capacity, the analysis signals a feasibility problem as much as a cost one.

Break-even is a floor, not a target. The natural next step is to set a profit goal and solve for the sales volume that achieves it: that volume equals the break-even units plus (target profit ÷ contribution margin per unit).