Calculate the margin of safety between intrinsic value and market price. Includes value scoring, max buy price, P/E & P/B analysis, and sensitivity table.
The margin of safety is the difference between a stock's intrinsic value and its market price, expressed as a percentage of intrinsic value. Coined by Benjamin Graham in "Security Analysis" and championed by Warren Buffett, it's the single most important concept in value investing — your cushion against errors in valuation, unexpected business problems, or market irrationality.
If you estimate a stock's intrinsic value at $150 and it trades at $100, your margin of safety is 33%. This means your estimate could be 33% too high and you'd still break even. The wider the margin, the lower your risk and the higher your potential return.
This calculator goes beyond a simple percentage calculation. It computes a value score (0–100) incorporating margin of safety, P/E ratio, P/B ratio, debt levels, and liquidity. The sensitivity table shows maximum buy prices across different intrinsic value estimates and MOS targets, helping you plan entry points even when your valuation has uncertainty.
Every valuation estimate contains uncertainty. The margin of safety protects against your own mistakes, deteriorating business conditions, and Mr. Market's mood swings. This calculator quantifies that protection and gives you a disciplined buy/avoid signal.
This tool is designed for quick, accurate results without manual computation. Whether you are a student working through coursework, a professional verifying a result, or an educator preparing examples, accurate answers are always just a few keystrokes away.
Margin of Safety = (Intrinsic Value − Price) / Intrinsic Value × 100 Max Buy Price = Intrinsic Value × (1 − Target MOS%) Upside = (Intrinsic Value − Price) / Price × 100
Result: Margin of safety = 33.3%, Max buy = $105
Intrinsic value of $150 vs $100 price gives a 33.3% margin of safety, exceeding the 30% target. The max buy price at 30% MOS is $105 — the stock is currently below this, so it passes the test.
Use consistent units throughout your calculation and verify all assumptions before treating the output as final. For professional or academic work, document your input values and any conversion standards used so results can be reproduced. Apply this calculator as part of a broader workflow, especially when the result feeds into a larger model or report.
Most mistakes come from mixed units, rounding too early, or misread labels. Recheck each final value before use. Pay close attention to sign conventions — positive and negative inputs often produce very different results. When working with multiple related calculations, keep intermediate values available so you can trace discrepancies back to their source.
Enter the most precise values available. Use the worked example or presets to confirm the calculator behaves as expected before entering your real data. If a result seems unexpected, compare it against a manual estimate or a known reference case to catch input errors early.
Graham suggested 30%+ for most stocks. Buffett requires 25% for high-quality businesses and 40%+ for more uncertain situations. Higher uncertainty demands wider margins.
Use our Intrinsic Value Calculator or DCF Calculator to estimate fair value from earnings, dividends, or cash flows. Multiple methods provide a valuation range.
Yes — a negative margin means the stock is trading above your estimated intrinsic value. Negative margins suggest the stock is overvalued.
They're related but calculated differently. MOS uses intrinsic value as the base; discount uses current price. A 33% MOS equals a 50% upside.
It combines five factors: margin of safety (30pts), valuation ratios (35pts), financial health (20pts), and liquidity (15pts) into a 0-100 score. Use this as a practical reminder before finalizing the result.
For stable, predictable businesses you might accept 20-25%. For cyclicals, turnarounds, or uncertain companies, insist on 40%+.