v0.10.0How to use
- Enter monthly fixed costs (the total of costs that go out every month regardless of sales, such as rent, salaries and insurance) and the variable cost ratio (the share of revenue taken by costs that scale with sales, such as materials, fees and packaging, in %).
- Enter monthly revenue to also see the estimated monthly profit (or loss), contribution margin and ratio, and the gap to break-even revenue. Leave revenue empty to get only the break-even revenue.
- Enter a target monthly profit to get the monthly revenue needed to keep that profit.
- Results update as you type. [Copy results] copies the detailed results table as text.
Example
With monthly revenue of 10,000,000, monthly fixed costs of 3,000,000 and a variable cost ratio of 40%, variable costs are 4,000,000, the contribution margin is 6,000,000 (ratio 60%) and the estimated monthly profit is 3,000,000. Break-even revenue is 3,000,000 ÷ 60% = 5,000,000, so current revenue is 5,000,000 above it. With a target monthly profit of 2,000,000, the revenue needed is (3,000,000 + 2,000,000) ÷ 60% = 8,333,334.
How it is calculated
| Item | Calculation |
|---|---|
| Variable costs | Monthly revenue × variable cost ratio (rounded up to the won) |
| Contribution margin | Monthly revenue − variable costs |
| Contribution margin ratio | 100% − variable cost ratio |
| Estimated monthly profit | Contribution margin − monthly fixed costs (before tax) |
| Break-even revenue | Monthly fixed costs ÷ contribution margin ratio (rounded up to the won) |
| Revenue needed for the target profit | (Monthly fixed costs + target monthly profit) ÷ contribution margin ratio (rounded up to the won) |
How costs are classified and taxed depends on your industry and business type, so check with a tax or accounting professional before important decisions.
Supported formats, limits and privacy
- Input: whole amounts of 0 or more (in KRW, commas allowed, up to 999,999,999,999 per field) and a variable cost ratio from 0 to 100% (up to two decimal places).
- This is a simple calculator that works only from the values you enter. Monthly profit is before tax: it does not account for VAT or income tax, depreciation, inventory changes or seasonality. Do not use it for tax or accounting decisions.
- Variable costs = monthly revenue × variable cost ratio (fractions of a won rounded up, once, so costs are never understated). Contribution margin = monthly revenue − variable costs, contribution margin ratio = 100% − variable cost ratio, monthly profit = contribution margin − monthly fixed costs.
- Break-even revenue = monthly fixed costs ÷ contribution margin ratio, rounded up to the won. Because variable costs are rounded up to the won, this is exactly the lowest whole-won revenue at which the monthly profit shown is 0 or more: at this revenue the profit is 0 or more, and 1 won less is a loss. Rounding variable costs half up would give contradictions when amounts are tiny or the ratio is close to 100% (for example fixed costs of 1, a ratio of 99.99% and revenue of 5,001 would show a profit of 0 yet say break-even was not reached), so they are rounded up. If the variable cost ratio is 100% there is no contribution margin, so the fixed costs can never be recovered and it is shown as unreachable.
- Revenue needed for the target profit = (monthly fixed costs + target monthly profit) ÷ contribution margin ratio, rounded up to the won; for the same reason it is the lowest whole-won revenue that leaves the target profit. All arithmetic uses integers, so there are no floating-point errors.
- What you enter is calculated only inside this browser. It is not sent to a server or stored, and it disappears when you close the page.
Frequently asked questions
How do I separate fixed and variable costs?
Costs that go out every month even with zero sales (rent, fixed salaries, insurance, subscriptions) are fixed costs. Costs that grow with sales (materials and product cost, payment and marketplace fees, packaging and shipping) are variable costs, and the variable cost ratio is their total divided by revenue, in %. For example, revenue of 10,000,000 with 4,000,000 of variable costs gives a ratio of 40%.
What is the contribution margin?
Revenue minus variable costs: the part that is available to pay the fixed costs. The revenue at which the contribution margin equals the fixed costs is the break-even revenue, and beyond it the contribution margin ratio of every extra won is profit.
What happens when the variable cost ratio is 100% or more?
Every sale costs as much as it brings in, so nothing is left to pay the fixed costs and break-even can never be reached. This calculator accepts a ratio of up to 100% and shows 100% as unreachable. You would need to raise prices or cut variable costs to bring the ratio below 100%.