Peter Lynch Fair Value - Definition, Formula & Calculator

What Is Peter Lynch Fair Value?

Peter Lynch Fair Value is a GuruFocus valuation estimate based on a simple idea popularized by legendary fund manager Peter Lynch: for a reasonably growing company, a fair price-to-earnings ratio is often close to its earnings growth rate. In shorthand, that means a stock may be fairly valued when its PEG ratio is about 1.

GuruFocus translates that idea into a per-share fair value estimate. For most non-bank companies, the calculation uses trailing 12-month earnings per share and the company’s five-year average EBITDA per Share growth rate. For banks, GuruFocus substitutes book value per share growth because EBITDA is generally not a meaningful banking metric.

The metric matters because it gives investors a quick way to connect valuation with growth. A company with a higher sustainable growth rate may deserve a higher earnings multiple than a slow-growing business. Peter Lynch Fair Value tries to express that relationship in dollar terms, making it easier to compare a stock’s current market price with a growth-adjusted estimate of fair value.

At its core, the intuition is straightforward: if a company is growing earnings at roughly 15% per year, a P/E ratio around 15 may be reasonable. If it is growing much more slowly, a lower multiple may be justified. If it is growing faster, a higher multiple may be warranted—up to a point.

A simplified version of the formula is:

Under GuruFocus’s methodology, the implied PEG ratio is set to 1, so the fair P/E multiple equals the selected growth rate.

How Is Peter Lynch Fair Value Calculated?

GuruFocus bases Peter Lynch Fair Value on the idea that:

Since price per share can be expressed as P/E multiplied by earnings per share, the fair value estimate becomes:

GuruFocus effectively assumes:

So the full intuition can also be written as:

With PEG fixed at 1, this simplifies back to:

Inputs used by GuruFocus

For non-bank companies, GuruFocus uses:

• EPS without NRI (TTM) as the earnings input
• 5-year average EBITDA per Share growth rate as the growth input

For banks, GuruFocus uses:

• EPS without NRI (TTM) as the earnings input
• 5-year average book value per share growth rate as the growth input

This distinction exists because EBITDA is generally not a useful operating measure for banks, while book value is often a more relevant anchor for financial institutions.

GuruFocus-specific calculation rules

GuruFocus applies several important rules to keep the metric within a practical range:

• If the 5-year growth rate is greater than 25%, GuruFocus uses 25%
• If the 5-year growth rate is smaller than 5%, GuruFocus does not calculate Peter Lynch Fair Value
• The earnings input is based on trailing 12-month results
• For quarterly reporters, TTM data is built from the most recent four quarters; for companies without enough quarterly data, annual data may be used as a substitute

These adjustments reflect the fact that the metric is intended for growing companies, especially those with moderate and reasonably durable growth. Historically, the “sweet spot” for this framework is often described as roughly 10% to 20% annual growth.

Peter Lynch Fair Value Trend Over Time

Looking at Peter Lynch Fair Value over time can be more informative than looking at a single snapshot. If the fair value estimate is rising steadily, that usually means the company’s earnings and growth profile are improving. If it is flat or falling, the business may be slowing, becoming less profitable or both.

Investors often compare the trend in Peter Lynch Fair Value with the trend in the stock price. When price rises much faster than the fair value estimate, the stock may be becoming more expensive relative to its growth-adjusted fundamentals. When fair value rises while the stock price lags, the shares may be becoming more attractive.

What Does Peter Lynch Fair Value Tell You?

Peter Lynch Fair Value tells you whether a stock’s current price looks reasonable relative to its recent earnings power and historical growth rate.

If the stock price is:

• Below Peter Lynch Fair Value, the shares may appear undervalued under this framework
• Near Peter Lynch Fair Value, the shares may appear fairly valued
• Above Peter Lynch Fair Value, the shares may appear overvalued

In practice, many investors look at the related ratio:

A ratio:

• Below 1 suggests the stock is trading below its Peter Lynch Fair Value
• Around 1 suggests the stock is trading near fair value
• Above 1 suggests the stock is trading above fair value

The metric is especially useful for investors who want a quick, growth-aware valuation check. Traditional P/E ratios can be misleading when viewed in isolation because a 20x multiple may be expensive for a company growing at 5% but reasonable for one growing at 20%. Peter Lynch Fair Value tries to account for that difference.

It can also be a useful screening tool. Investors may use it to identify companies whose prices have not kept up with their earnings and growth trends, then follow up with deeper analysis of business quality, balance sheet strength and competitive position.

Limitations of Peter Lynch Fair Value

Peter Lynch Fair Value is simple and intuitive, but it has important limitations.

First, it depends heavily on the growth rate assumption. A company’s past five-year growth rate may not reflect its future growth. If growth is slowing, the metric can overstate fair value. If growth is temporarily depressed, it can understate fair value.

Second, the metric works best for growing companies with relatively stable economics. It is less useful for:

• highly cyclical businesses
• turnaround situations
• commodity producers with volatile earnings
• companies with inconsistent margins
• mature businesses with little or no growth

Third, the earnings input matters. GuruFocus uses EPS without NRI, which helps reduce distortion from non-recurring items, but earnings can still be affected by accounting choices, share repurchases and temporary business conditions.

Fourth, the metric is not the same as a full intrinsic value model. It does not explicitly account for:

• interest rates
• cost of capital
• reinvestment needs
• competitive durability
• leverage
• cash flow conversion
• terminal value assumptions

That means Peter Lynch Fair Value should be viewed as a heuristic, not a complete valuation model.

Fifth, investors should not confuse Peter Lynch Fair Value with the Peter Lynch Chart. On the Peter Lynch Chart, the earnings line is often drawn using a fixed P/E of 15. Peter Lynch Fair Value is different: it uses a P/E multiple tied to the company’s growth rate, not a fixed multiple.

Finally, cross-industry comparisons can still be misleading. Even if two companies have similar growth rates, their risk, capital intensity and earnings quality may be very different.

Real-World Example

A useful way to understand Peter Lynch Fair Value is to compare a steady grower with a company whose growth is harder to interpret.

Consider Apple (AAPL). Apple has historically combined strong earnings power, large free cash flow and periods of solid per-share growth. For a company like this, Peter Lynch Fair Value can serve as a quick check on whether the market price is broadly in line with its growth-adjusted earnings profile. If Apple’s share price rises much faster than its trailing earnings and five-year per-share growth, the stock’s price-to-Peter-Lynch-fair-value ratio may expand and suggest richer valuation.

Now compare that with a more cyclical business such as Exxon Mobil (XOM). Exxon’s earnings can swing sharply with oil and gas prices. In that setting, a five-year historical growth rate may be heavily influenced by the commodity cycle rather than by durable underlying business momentum. Peter Lynch Fair Value may still be calculable, but the result should be interpreted much more cautiously.

That contrast shows where the metric is most helpful. It tends to be more informative for companies with relatively stable, repeatable growth than for businesses whose earnings are dominated by macro cycles or one-time rebounds.

FAQs

What is a good Peter Lynch Fair Value?

Peter Lynch Fair Value itself is a dollar estimate, so investors usually judge it by comparing it with the current stock price. In general, a stock may look more attractive when its market price is below its Peter Lynch Fair Value, or when its price-to-Peter-Lynch-fair-value ratio is below 1. That said, there is no universal cutoff. The metric is most useful when combined with business quality, growth durability and peer analysis.

What is the difference between Peter Lynch Fair Value and related metrics?

Peter Lynch Fair Value is a growth-adjusted valuation shortcut. It differs from:

• P/E ratio, which shows how much investors are paying for current earnings but does not directly adjust for growth
• PEG ratio, which compares P/E to growth; Peter Lynch Fair Value effectively assumes PEG = 1
• DCF valuation, which estimates intrinsic value by discounting future cash flows
• Peter Lynch Chart, which often uses a fixed P/E of 15 for the earnings line rather than a growth-based multiple

So Peter Lynch Fair Value is simpler than a DCF and more valuation-oriented than a raw PEG ratio.

Can Peter Lynch Fair Value be negative?

Yes. If trailing 12-month EPS is negative, the resulting fair value estimate can also be negative or not economically meaningful. In practice, the metric is not very useful for unprofitable companies. GuruFocus also does not calculate it when the relevant five-year growth rate is below 5%.

How should investors use Peter Lynch Fair Value?

Investors should use it as a first-pass valuation tool, not a final answer. It can help identify stocks whose prices look out of line with their earnings and growth history. After that, investors should confirm whether the growth is sustainable, whether earnings quality is high and whether the business deserves a premium or discount relative to the simple PEG=1 framework.

Summary

Peter Lynch Fair Value is a practical valuation shortcut built on a simple principle: a growing company’s fair P/E ratio may roughly match its growth rate. GuruFocus applies that idea by combining trailing 12-month earnings with a five-year growth measure—typically EBITDA-per-share growth for non-banks and book-value-per-share growth for banks.

The metric can be useful because it links valuation to growth in a way that is easy to understand and easy to compare across time. But it is still only a heuristic. It works best for profitable companies with reasonably stable growth and should always be used alongside other valuation methods, historical context and industry comparisons.

Sources

1. Peter Lynch with John Rothchild, One Up On Wall Street (Simon & Schuster), https://www.simonandschuster.com/books/One-Up-On-Wall-Street/Peter-Lynch/9780743200400
2. Investopedia, “PEG Ratio: What It Is and the Formula,” https://www.investopedia.com/terms/p/pegratio.asp
3. Corporate Finance Institute, “PEG Ratio,” https://corporatefinanceinstitute.com/resources/valuation/peg-ratio-overview/
4. Morningstar, “Price/Earnings-to-Growth (PEG) Ratio,” https://www.morningstar.com/investing-definitions/peg-ratio
5. Apple Inc. Investor Relations, Annual Reports and SEC Filings, https://investor.apple.com/sec-filings/default.aspx
6. Exxon Mobil Investor Relations, Annual Reports and SEC Filings, https://corporate.exxonmobil.com/investors
7. U.S. Securities and Exchange Commission, “Form 10-K,” https://www.investor.gov/introduction-investing/investing-basics/glossary/form-10-k