The break-even point is the number of units (lessons, orders, subscriber-months) whose contribution margin exactly covers your total fixed costs for a period. Formula: break-even volume = total fixed costs ÷ contribution margin per unit, rounded up. Below that number the period loses money; above it, every extra unit adds its contribution margin to profit. For an online business the useful version is monthly, not yearly: a profitable year can hide several months below the line. Below are the formula, a worked example on an online tutoring school, and the two numbers that belong next to it: margin of safety and operating leverage.
The formula
QBE=cF,c=QS−V
where F is the period's total fixed costs, c the contribution margin per unit, S sales, V variable costs and Q units sold.
Contribution margin per unit, not the price. It is the price minus the costs that come with each unit, see contribution margin explained.
Total fixed costs: everything that doesn't grow with one more unit this month, including the marketing budget you set and step costs at their current level, see fixed vs variable costs.
For a subscription the unit is a subscriber-month: monthly price minus per-subscriber costs (payment fee, usage-based hosting, support that scales with customers). Break-even subscribers = fixed costs ÷ that number.
A worked example: an online tutoring school
Klasna is an online tutoring school: families buy packages of 1:1 video lessons, and tutors are paid for each lesson delivered. Its year, September to August, closed with an operating profit of 744,174.72 UAH. The CEO's conclusion: summer doesn't matter. Let's check month by month.
March. Families paid 4,868,640 UAH for 7,840 lessons. Variable costs: tutor payouts 3,136,000 + payment fees 121,716 + video and AI 243,040 = 3,500,756 UAH. That leaves a contribution of 1,367,884 UAH, or 174.48 UAH per lesson. Fixed costs: support coordinators 114,000 + team salaries 540,000 + office and tools 84,000 + marketing 300,000 = 1,038,000 UAH.
QBE=174.481038000=5949.1→5950 lessons
Round up: there is no such thing as part of a lesson. The same steps for two more months:
UAH
March
May
July
Fixed costs
1,038,000
1,096,000
850,000
Contribution per lesson
174.48
175.40
176.35
Break-even, lessons
5,950
6,249
4,820
Lessons delivered
7,840
9,620
2,600
Operating profit
329,884
591,348
−391,490
July has the lowest line of the three (two coordinators instead of four, 150,000 UAH of marketing), yet it delivered only 2,600 lessons, just over half of its break-even point. Its contribution of 458,510 UAH against 850,000 of fixed costs is a loss of 391,490 UAH.
Five months sit below their line: September, December, June, July and August, losing 1,029,144.15 UAH together. A strong spring covers it. With 20% fewer lessons from February to May, the same summer would wipe out the year's profit.
Margin of safety: how far from the line
The margin of safety shows how far sales can fall before you reach break-even, as a share of actual volume:
MoS=QQ−QBE=78407840−5950=24.11%
March could lose almost a quarter of its lessons and still cover every fixed cost. May, the exam peak, had 35.04%. July had none: it was 2,220 lessons short.
In March, 174.48 UAH of contribution per lesson covers 1,038,000 UAH of fixed costs at 5,950 lessons; 7,840 lessons leave a 24.11% margin of safety and 329,884 UAH of profit
Operating leverage: why profit moves faster than sales
Operating leverage is contribution ÷ operating profit. For March: 1,367,884 ÷ 329,884 = 4.15. With 10% more lessons, contribution grows by about 136,788 UAH while fixed costs stay put, so profit grows by about 41%. Ten percent fewer lessons cut it by the same 41%. Leverage is roughly 1 ÷ margin of safety (1 ÷ 0.2411 ≈ 4.15): the closer a month is to break-even, the harder its profit swings.
Break-even analysis: what moves the break-even point
Only two things: total fixed costs and contribution per unit. Selling more doesn't move the line; it moves you along it.
A fixed-cost decision has a price in units. Add 20,000 UAH of ads in March and break-even goes from 5,950 to 6,064 lessons (1,058,000 ÷ 174.48 = 6,063.8, rounded up).
A discount lowers contribution per unit, so the same fixed costs need more units.
Step costs jump. Klasna adds a support coordinator (38,000 UAH a month) for every started 400 active learners. A fourth one in March would add about 218 lessons to the line (38,000 ÷ 174.48 ≈ 217.8).
Honest limits
One average contribution per unit. March mixes subjects and package sizes. If customers shift to cheaper packages, contribution per lesson falls and the line rises.
Fixed only within a range. Double the customers and you need more support people, maybe more of the team.
Profit, not cash. Prepaid packages bring money before lessons happen; break-even says nothing about the bank balance.
Key takeaways
Break-even volume = total fixed costs ÷ contribution margin per unit, rounded up.
Calculate it per month: a yearly profit can hide months below the line.
Report margin of safety and operating leverage next to it.
Every fixed-cost decision and every discount has a price in units per month.
FAQ
What is the break-even point formula?
Total fixed costs for the period divided by contribution margin per unit (price minus variable costs per unit), rounded up to a whole unit.
How do I calculate break-even for a subscription business?
Use a subscriber-month as the unit: monthly price minus per-subscriber variable costs. Divide monthly fixed costs by that number to get the subscribers you need.
What is the difference between the break-even point and the margin of safety?
The break-even point is the line; the margin of safety is how far your actual volume sits above it, as a percentage.
Learn it hands-on
The lesson Break-even and margin of safety works through Klasna's twelve months with the full dataset and numeric exercises checked instantly. It is part of the course Finance for Product People: From Unit Economics to Business Cases, which starts with what one lesson leaves.
