Educational business arithmetic
See when volume covers the fixed costs.
Calculators and plain-language guides for break-even analysis, contribution margin and cost behavior. Every formula is visible, every example is labeled as illustrative, and your inputs never leave the browser.
Open the break-even calculator →Start with the question you have
Break-even calculator
Units and revenue needed for contribution to cover fixed costs, plus units for a target profit.
Open the tool → CALCULATORContribution margin calculator
Contribution per unit, total contribution, contribution margin ratio and operating income.
Open the tool → GUIDEContribution margin explained
Per-unit, total and ratio forms, the contribution-format income statement and common mistakes.
Read the guide → GUIDEBreak-even in units vs revenue
When to count units, when to use sales dollars, and how a sales mix changes the answer.
Read the guide → GUIDEFixed vs variable costs
Classify costs, split mixed costs with the high-low method and respect the relevant range.
Read the guide → GUIDETarget profit & margin of safety
Volume for a profit goal, the cushion above break-even and what operating leverage means.
Read the guide →The core idea in one worked example
Suppose (illustratively) a product sells for $40, each unit carries $25 of variable cost, and the period's fixed costs are $5,000. Each sale leaves $15 of contribution margin toward the fixed costs, which is a 37.5% contribution margin ratio ($15 ÷ $40).
Break-even revenue = fixed costs ÷ contribution margin ratio = 5,000 ÷ 0.375 ≈ $13,333.33
Below 334 units the model shows an operating loss; above it, each extra unit adds $15 to operating income. The same three inputs (price, variable cost per unit and fixed costs) drive every page on this site.
What this site covers, and what it does not
- Covers: cost-volume-profit (CVP) arithmetic: contribution margin, break-even in units and dollars, target profit, margin of safety, operating leverage and separating fixed from variable costs.
- Does not cover: pricing strategy, margin vs markup conversions (see the sibling site ameti.capital), tax, financing, valuation or any investment, capital advisory, succession or M&A service.
Definitions follow standard managerial-accounting usage; each guide links its sources, such as the free OpenStax Principles of Accounting, Volume 2: Managerial Accounting textbook. Read how these resources are prepared or browse all guides and all calculators.