How Break-Even Analysis Works
Every unit you sell pays for its own variable costs first; whatever is left — the contribution margin — goes toward the fixed costs that exist whether you trade or not. Break-even is simply the point where those contributions have finally covered the fixed costs in full.
Break-even units = Fixed costs ÷ Contribution margin
Break-even revenue = Break-even units × Price
Margin of safety (%) = ((Actual − Break-even) ÷ Actual) × 100
A workshop has $12,000 in monthly fixed costs. Each item sells for $40 and costs $25 in materials and fees, contributing $15. Break-even is 12,000 ÷ 15 = 800 units, or $32,000 in revenue. Selling 1,000 units gives a 20% margin of safety and $3,000 profit.
The Three Levers
Break-even moves in only three ways, and knowing which one you can pull is the whole value of the exercise:
- Raise the price. The most powerful lever, because it feeds contribution directly — but it risks volume. Test the trade-off with the margin calculator.
- Cut variable costs. Better suppliers, less waste, cheaper payment processing. Every dollar saved per unit is a dollar of contribution.
- Cut fixed costs. Slow and often painful, but it lowers the bar permanently and reduces risk in bad months.
Sensitivity: Small Price Changes, Big Effects
| Price | Contribution | Break-even units |
|---|---|---|
| $36 (−10%) | $11 | 1,091 |
| $38 (−5%) | $13 | 924 |
| $40 (base) | $15 | 800 |
| $42 (+5%) | $17 | 706 |
| $44 (+10%) | $19 | 632 |
With $12,000 fixed costs and $25 variable cost: a 10% price cut raises the units you must sell by 36%, while a 10% rise lowers it by 21%. This asymmetry is why discounting needs a volume plan behind it, and why price increases are so much more forgiving than they feel.
In practice How a candle maker decides whether a market stall is worth it
A stall costs $180 for the weekend — a fixed cost that exists whether or not anything sells. Each candle sells for $24 and costs $9 in wax, wick, jar and label, contributing $15 toward that $180.
Break-even is 180 ÷ 15 = 12 candles. Everything after the twelfth adds a clean $15 of profit. Selling 40 candles means (40 × 15) − 180 = $420 for the weekend, with a 70% margin of safety.
It also answers the discount question instantly: drop the price to $20 and contribution falls to $11, pushing break-even to 17 candles. The "small" $4 discount costs five extra sales before you earn anything.
Frequently Asked Questions
What is the break-even point?
The sales volume at which total revenue exactly covers total costs, so profit is zero. Below it you lose money; above it, every additional unit adds its contribution margin straight to profit.
How do you calculate the break-even point?
Divide fixed costs by the contribution margin per unit (price minus variable cost per unit). With $12,000 of fixed costs, a $40 price and $25 variable cost, contribution is $15 and break-even is 12,000 ÷ 15 = 800 units.
What is contribution margin?
What one unit contributes toward fixed costs after paying its own variable costs: price minus variable cost per unit. Until fixed costs are covered it pays down the overhead; after that, it is profit.
What is the difference between fixed and variable costs?
Fixed costs stay the same whatever you sell — rent, insurance, salaried staff, software. Variable costs scale with each unit — materials, packaging, payment fees, commission. Some costs are mixed; split them into the portion that scales and the portion that does not.
What is margin of safety?
How far your actual sales sit above break-even, as a percentage. A margin of safety of 25% means sales could fall by a quarter before you start losing money. Low margins of safety mean fragile businesses.
Why does my break-even point rise when I offer discounts?
Discounting cuts the price but not the variable cost, so contribution margin falls and each unit pays down less overhead. A 10% discount on a $40 item with $25 variable cost cuts contribution from $15 to $11 — pushing break-even up by more than a third.
Sources & Further Reading
- Cost-volume-profit analysis — Horngren, Cost Accounting: A Managerial Emphasis
- Break-even analysis for business plans — U.S. Small Business Administration
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The CalculatorsGuide Editorial Team. (2026). Break-Even Calculator. CalculatorsGuide. Retrieved from https://www.calculatorsguide.com/finance/break-even-calculator/