Finance
Break-even calculator
The break-even point is where contribution margin finally covers fixed costs. Everything sold after that point is profit.
Contribution margin is the engine
break-even units = fixed costs ÷ contribution margin
Every unit you sell contributes its margin toward the fixed costs. Once enough units have been sold to cover them entirely, the fixed costs are paid and each additional unit's margin drops straight to profit. That switch is the break-even point.
The ratio version — contribution margin divided by price — tells you what proportion of each sale is available to cover overhead. A 60% contribution margin means $0.60 of every dollar of revenue is working for you; the rest was consumed producing the sale.
Sorting fixed from variable
Fixed costs do not move with volume in the short run: rent, salaried staff, insurance, software subscriptions, loan payments. Variable costs scale with each unit: materials, packaging, shipping, payment processing fees, hourly labour tied directly to production.
Several costs are genuinely mixed. A utility bill has a standing charge plus usage. Sales staff on base plus commission are part of each. Split them rather than forcing them into one column — putting a variable component in the fixed bucket understates how quickly costs rise with growth.
Watch for costs that are fixed only within a range. Your current premises might handle 5,000 units a month; at 5,001 you need a second unit and the fixed cost steps up. These step costs mean there can be more than one break-even point as a business scales.
Lowering the break-even point
Three levers, in rough order of impact per unit of effort:
- Raise the price. A price increase flows entirely into contribution margin. Lifting the price above from $45 to $50 cuts break-even from 297 units to 250, a 16% reduction, without touching costs.
- Cut variable cost. Equally direct, but usually harder — supplier terms, packaging, process efficiency.
- Cut fixed costs. Reduces the target proportionally, and it is the only lever that helps when volumes are already low.
Cutting the price to sell more units works only if the volume increase is large enough to offset the smaller margin, and the required increase is usually bigger than people expect. Dropping from $45 to $40 here cuts margin from $27 to $22, so you need 23% more sales just to stand still.
Margin of safety
Once you know the break-even point, compare it against actual or forecast sales. The gap between them, expressed as a percentage of sales, is your margin of safety — how far revenue can fall before the business starts losing money. A margin of safety under 20% means a modest downturn puts you underwater, which is a useful thing to know before signing a lease.
Common questions
How do I calculate break-even for a service business?
Treat a billable hour or an engagement as the unit. Variable cost is whatever you pay directly to deliver it — contractor time, per-project software, travel. Your own salary belongs in fixed costs if you draw it regardless of volume.
Should I include my own salary in fixed costs?
If you need to pay yourself, yes. A break-even point calculated without the founder’s income tells you when the business stops losing money, not when it becomes viable. Many businesses look profitable only because the owner is working unpaid.
What about products with different margins?
Use a weighted average contribution margin based on your actual sales mix. The result is only valid while that mix holds — if the low-margin line grows faster, the real break-even point rises even though nothing else changed.
How long should it take to break even?
There is no standard answer, but the more useful version of the question is how much cash you need to survive until you get there. Multiply the monthly shortfall by the number of months you expect it to last, then add a substantial buffer, because it nearly always takes longer than planned.