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Free financial calculator

Overvalued or Undervalued? Valuation Calculator

Clear valuation zones from fair value and margin of safety - not investment advice.

Also available in German: Ist die Aktie über- oder unterbewertet? - Bewertungs-Rechner →

Inputs

Share price

Also called: Stock price, market price

Where to find it: Any finance site (Google/Yahoo Finance) — the current trading price per share.

How to derive: Set by the market; just enter the current price per share.

Share price

Also called: Stock price, market price

Where to find it: Any finance site (Google/Yahoo Finance) — the current trading price per share.

How to derive: Set by the market; just enter the current price per share.

%

Margin of safety

Also called: Safety buffer

Where to find it: A buffer you choose — not a balance-sheet figure.

How to derive: Discount on fair value (e.g. 25%) to absorb errors. Graham/Buffett principle.

Result, live

Gap to fair value
Undervalued below
Overvalued above

Discipline beats forecasting: the margin protects against model and data errors. Our calculator provides fair value for 35,000+ stocks.

This calculator answers the simplest and most important question: is the stock too cheap or too expensive? You enter the current price, a fair value and your margin of safety — and get a clear verdict in three zones: undervalued, fair or overvalued.

How the formula works

The calculator sets two thresholds around the fair value: a buy line below fair value minus your margin of safety, and a sell line a little above it:

Undervalued below = fair value × (1 − margin)
Overvalued above = fair value × 1.10
Gap = (fair value − price) ÷ price

Example: fair value $100, margin 20% → buy line $80, sell line $110. A price of $80 sits right at the line: undervalued, with a +25% gap to fair value.

How to read the result

The verdict falls into three zones:

  • Undervalued — the price is below fair value minus the margin. Here you get a buffer for errors for free.
  • Fairly valued — the price sits between the lines, neither clearly cheap nor clearly expensive.
  • Overvalued — the price is well above fair value; expectations are high.

The positive or negative gap shows in percent how far the price is from fair value.

What to watch out for

The verdict is only ever as good as the fair value behind it:

  • Fair value is an estimate. Wrong assumptions give a wrong verdict — garbage in, garbage out.
  • The margin is your protection. 20–30% cushions model and data errors; without a margin the line is arbitrary.
  • Cheap isn't the same as good. A stock can be rightly cheap if the business is shrinking.

Frequently asked questions

What is the margin of safety?
The discount you demand off fair value before buying — typically 20–30%. It protects against errors in model and data: if you are wrong, you still have a buffer.
Why is the sell line only 10% above fair value?
Because selling needs less buffer than buying. When a stock trades clearly above fair value, the risk/reward is worse — the 10% marks that zone without flagging every small overshoot.
Where do I get the fair value?
From a valuation model — or straight from our Fair Value Calculator, which provides a ready fair value per share for 35,000+ stocks. Enter it here and get the verdict instantly.