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Finance Calc Kit
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Margin of Safety Calculator

Calculate margin of safety in dollars, percentage, and units for business sales and value investing analysis.

Analysis mode

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Margin of safety

30.0%

Buffer above break-even or intrinsic value

Margin of safety ($)

$150,000.00

Margin of safety (units)

3,000 units

Report tool

What margin of safety means in business and investing

Margin of safety measures the buffer between your current position and a critical threshold. In cost accounting, it is the gap between actual sales and break-even sales. In value investing, popularized by Benjamin Graham, it is the discount between intrinsic value and market price. A larger margin absorbs forecasting errors, demand shocks, or valuation uncertainty.

Use the sales mode to quantify how much revenue cushion exists above break-even, optionally converting that dollar buffer into units. Use the investing mode to see whether a stock trades below your estimated fair value. To measure the worst peak-to-trough decline in a portfolio and the gain required to recover, try the maximum drawdown calculator. For break-even unit and revenue targets, try the break-even calculator. For contribution margin and operating leverage, see the contribution margin calculator.

Margin of safety formulas

Margin of Safety ($)=Actual Sales−Break-Even Sales\text{Margin of Safety (\$)} = \text{Actual Sales} - \text{Break-Even Sales}
Margin of Safety (%)=Actual Sales−Break-Even SalesActual Sales×100\text{Margin of Safety (\%)} = \frac{\text{Actual Sales} - \text{Break-Even Sales}}{\text{Actual Sales}} \times 100

For value investing, replace actual sales with intrinsic value per share and break-even sales with the current market price. A 25% margin of safety on a $100 intrinsic value means buying at $75 or below.

Worked example (sales mode)

A company expects $500,000 in revenue with break-even at $350,000 and a $50 selling price per unit. The dollar margin of safety is $150,000 (30% of actual sales). At $50 per unit, that equals 3,000 units of sales cushion before the business reaches break-even.

Frequently asked questions

What is a good margin of safety for stocks?
Graham often sought a 33% discount to intrinsic value, though modern practitioners vary by sector, growth rate, and conviction. Higher uncertainty generally warrants a wider buffer.
Can margin of safety be negative?
Yes. Negative values mean actual sales fall below break-even or the market price exceeds your intrinsic value estimate. That signals operating losses or an overvalued investment by your model.
How is margin of safety different from profit margin?
Profit margin is profit divided by revenue on each sale. Margin of safety measures how far total sales or price can fall before you hit break-even or overpay relative to intrinsic value.
Should I include fixed costs when estimating break-even sales?
Yes. Break-even sales should cover all fixed and variable costs at your expected volume. The contribution margin calculator helps derive break-even from unit economics.

Resources and references

The formulas and methods in this calculator were checked against these independent sources.