Free Margin of Safety Calculator
Calculate your margin of safety using sales, break-even revenue, business costs, or an investment’s estimated intrinsic value.
Choose a calculation method below. Business calculations use US dollars. Investment prices are also expressed in US dollars per share.
Your Results
Your calculation details will appear here.
Enter values and click Calculate.
Business results assume costs and contribution margins remain valid over the relevant sales range. Investment results depend on the intrinsic value estimate you enter.
How to Use the Margin of Safety Calculator
This calculator supports margin of safety analysis for business accounting and stock valuation.
Step 1: Choose a Calculation Method
Select Sales Revenue if you already know your actual sales and break-even sales figures.
Select Units and Costs to calculate margin of safety using selling price, variable cost, fixed costs, and units sold.
Select Contribution Margin if you know your sales, fixed costs, and contribution margin ratio.
Select Stock Investment to compare market price with an estimated intrinsic value.
Step 2: Enter Your Values
Enter the required figures in the fields displayed for your selected mode.
Use consistent accounting periods for sales and costs.
Step 3: Click Calculate
The calculator displays the margin of safety, supporting values, and a breakdown of the formula.
Step 4: Review the Result
A positive business margin of safety means sales exceed the calculated break-even level.
A negative result means sales are below break-even.
For stocks, a positive margin of safety means the market price is below your estimated intrinsic value.
Margin of Safety Formula
Margin of safety has different applications in business accounting and investing.
Business Margin of Safety Formula
Margin of Safety ($) = Actual Sales – Break-Even Sales
To calculate the percentage:
Margin of Safety (%) = (Actual Sales – Break-Even Sales) ÷ Actual Sales × 100
For example, sales of $120,000 and break-even revenue of $90,000 produce a margin of safety of $30,000.
The percentage is 25%.
Break-Even Sales Formula
If you know fixed costs and the contribution margin ratio:
Break-Even Sales = Fixed Costs ÷ Contribution Margin Ratio
Convert the contribution margin percentage to a decimal before dividing.
Break-Even Units Formula
For a single product:
Contribution per Unit = Selling Price – Variable Cost per Unit
Break-Even Units = Fixed Costs ÷ Contribution per Unit
The calculator reports the theoretical break-even quantity and uses the unrounded quantity to calculate break-even revenue.
For practical whole-unit planning, round the break-even quantity upward.
Margin of Safety in Units
Margin of Safety (Units) = Actual Units Sold – Break-Even Units
This formula is particularly useful for single-product businesses.
Stock Margin of Safety Formula
For an investment:
Margin of Safety (%) = (Intrinsic Value – Market Price) ÷ Intrinsic Value × 100
You can also calculate the dollar difference:
Dollar Difference = Intrinsic Value – Market Price
Target Purchase Price Formula
To calculate the maximum price corresponding to a chosen margin of safety:
Target Price = Intrinsic Value × (1 – Target Margin of Safety)
For example, an intrinsic value of $100 and a target margin of safety of 25% produce a target price of $75.
This is a valuation calculation, not an investment recommendation.
Business Margin of Safety Example
Suppose a business reports the following figures:
- Actual sales: $120,000
- Break-even sales: $90,000
Step 1: Calculate the Dollar Margin
$120,000 – $90,000 = $30,000
Step 2: Calculate the Percentage
$30,000 ÷ $120,000 × 100 = 25%
Final Result
The business has a margin of safety of $30,000, equivalent to 25% of sales.
Under unchanged cost and revenue assumptions, sales could decline by 25% before reaching break-even.
Stock Margin of Safety Example
Suppose an investor estimates a stock’s intrinsic value at $100 per share.
The current market price is $70 per share.
Step 1: Calculate the Price Difference
$100 – $70 = $30
Step 2: Calculate Margin of Safety
$30 ÷ $100 × 100 = 30%
Step 3: Calculate a Target Price
If the investor specifies a 25% margin-of-safety target:
$100 × (1 – 0.25) = $75
Final Result
The stock trades 30% below the entered intrinsic value estimate.
The calculated price corresponding to a 25% target discount is $75 per share.
Neither figure establishes the stock’s actual future value or limits potential losses.
Margin of Safety Comparison Table
The following examples assume actual sales of $100,000.
| Actual Sales | Break-Even Sales | Margin of Safety ($) | Margin of Safety (%) |
|---|---|---|---|
| $100,000 | $50,000 | $50,000 | 50% |
| $100,000 | $60,000 | $40,000 | 40% |
| $100,000 | $70,000 | $30,000 | 30% |
| $100,000 | $80,000 | $20,000 | 20% |
| $100,000 | $90,000 | $10,000 | 10% |
| $100,000 | $100,000 | $0 | 0% |
Examples assume the relevant cost structure remains unchanged.
Frequently Asked Questions
What is margin of safety?
In accounting, margin of safety measures how much actual or budgeted sales exceed break-even sales.
In investing, it commonly measures the discount between estimated intrinsic value and market price.
How do you calculate margin of safety?
For a business, subtract break-even sales from actual sales.
Divide the difference by actual sales and multiply by 100 to calculate the percentage.
Can margin of safety be negative?
Yes. A negative business margin of safety means actual sales are below break-even.
For investments, a negative result means market price exceeds the entered intrinsic value estimate.
What does a 25% margin of safety mean?
In business accounting, it means sales exceed break-even sales by an amount equal to 25% of current sales.
In investing, it means the market price is 25% below the entered intrinsic value estimate.
What is the difference between margin of safety and profit margin?
Profit margin measures profit relative to revenue.
Business margin of safety measures the distance between actual sales and break-even sales.
How do you calculate break-even sales?
Divide fixed costs by the contribution margin ratio expressed as a decimal.
For example, $25,000 in fixed costs and a 40% contribution margin ratio produce break-even sales of $62,500.
Can margin of safety exceed 100%?
In standard business calculations with positive sales and nonnegative break-even revenue, the margin of safety cannot exceed 100%.
The same upper limit applies to the investment formula when intrinsic value and market price are positive.
What happens when actual sales are zero?
The dollar margin of safety can still be calculated.
However, the percentage is undefined because actual sales appear in the denominator.
Does a stock’s margin of safety guarantee a profit?
No. Intrinsic value is an estimate and may change as new information becomes available.
A calculated discount does not guarantee future investment returns or prevent losses.
Can I use this calculator for a small business?
Yes. Use the sales, unit economics, or contribution margin mode according to the information available.
For multiple products, unit-based calculations require additional assumptions about sales mix. The revenue-based contribution margin method can use an appropriate weighted-average contribution ratio.
Related Calculators
Educational calculations only. Verify business costs and break-even assumptions against your records. Investment calculations are based entirely on user-entered valuations.