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About the Fair Value Calculator

We build evidence-based fair value and quality research for self-directed investors, independent, transparent and deliberately conservative. The goal: give retail investors the same depth usually reserved for professionals, without hype and without promises.

In short

Independent fair value and quality research for self-directed investors, since 2016. Every number traces back to real reported data. Browsing and valuing individual stocks is free, Pro adds ongoing monitoring and alerts.

Our mission

Most investing tools show prices and opinions. We show a transparent intrinsic value: a fair value from 26 independent valuation models, a quality score from 37 fundamental factors, and an honest evidence status, for about 35,000+ stocks worldwide. Every number traces back to real reported data.

The original, on public record since 2016

Many products claim a long history. Ours can be read. On 20 March 2016, fairvalue-calculator.com went online; one day later Dr. Peter Klein presented the calculator in the German Wertpapier-Forum and asked for tests. The thread still exists: eight pages from ten years, with dated posts, concrete numbers, errors found by strangers, and the answers given at the time.

Publicly documented since 20 March 2016: grown from a self-developed online calculator into a global platform for fair value and quality over more than ten years.

We did not invent fair value: Benjamin Graham described the intrinsic value of a stock in the 1930s. Our contribution is the product, the combination of many models into one figure anyone can use, and its long public development. Large financial websites now show automatic fair value figures too. We take that as confirmation of the idea. When you read "Fair Value Calculator", this is the one that has carried the name in public since March 2016.

Timeline with sources

2004Aged 14 in Graz, Peter Klein starts studying stocks and reads more than a hundred investing books over the following years. handbook 2020 [9]
20 March 2016fairvalue-calculator.com goes online: a free calculator that estimates intrinsic value from earnings per share and growth, based on an extended Graham formula tuned to approximate a discounted cash flow valuation. dated in public at the time [1]
21 March 2016Public launch post in the German Wertpapier-Forum (user name petz00711), asking for tests. The very first post already invites users to publish their calculated fair values so that other investors can find new ideas. dated in public at the time [1]
30 March 2016Start of the public wikifolio "Fair Value Calculator": a public model portfolio run by the method; the creation date is recorded by the provider. dated in public at the time [10] [9]
8 May 2019Relaunch after two years of development: automatic valuation from a large database, screener, watchlist, two languages, plus a premium area for diversified portfolios. dated in public at the time [4]
2020The handbook "Die Fair Value Calculator Methode" (77 pages) documents the method and the tools: automatic fair values for more than 33,000 stocks, market analysis, sector analysis, quality check, total score, watchlist and portfolio manager. handbook 2020 [9]
8 January 2021Several valuation methods are computed automatically and combined into one fair value. A video series of six lessons follows. dated in public at the time [6]
8 September 2025AI valuation for soft factors: brand strength, management quality, competitive advantages and scalability complement the numbers. dated in public at the time [6]
28 July 2026In its tenth year, the complete rebuild: about 35,000 stocks worldwide, valuation and quality as two separate questions, a range from cautious to optimistic case, an evidence status per stock, a portfolio optimizer and a 34-year test. dated in public at the time [6] [7]
October 2026Current state: 26 valuation models, up to 37 quality factors, about 35,000 valued stocks, an AI verdict with the main risk per stock, user comments and votes, a free academy of 16 lessons and a connection for AI assistants. own account [11]
Show every step from 2004 to today
2004Aged 14 in Graz, Peter Klein starts studying stocks and reads more than a hundred investing books over the following years. handbook 2020 [9]
2004 to 2009Apprentice years: losses with leveraged certificates, a forgotten demo portfolio of blue chips that quadruples between 2004 and 2008, and a lost short bet at the bottom of the financial crisis. The conclusion: long-term investing by value. handbook 2020 [9]
2013During his studies he writes his own valuation formulas by hand and runs first backtests. This is his own account; there is no public third-party record dated 2013. own account [9]
20 March 2016fairvalue-calculator.com goes online: a free calculator that estimates intrinsic value from earnings per share and growth, based on an extended Graham formula tuned to approximate a discounted cash flow valuation. dated in public at the time [1]
21 March 2016Public launch post in the German Wertpapier-Forum (user name petz00711), asking for tests. The very first post already invites users to publish their calculated fair values so that other investors can find new ideas. dated in public at the time [1]
21 to 26 March 2016Forum members test the calculator at once and find weaknesses: too little openness about the formula, implausible results for very small earnings, the stock split problem, and two inputs being too few for cyclical companies. On 22 March the calculator is adjusted for small earnings. dated in public at the time [1]
30 March 2016Start of the public wikifolio "Fair Value Calculator": a public model portfolio run by the method; the creation date is recorded by the provider. dated in public at the time [10] [9]
3 June 2016First larger backtest published in the forum (33 German and US stocks, 2005 to 2015). A self-run study on a small sample, rightly questioned in the forum; today replaced by the 34-year test, adjusted for companies that no longer exist. dated in public at the time [2]
12 to 15 June 2016Three helper calculators (weighted earnings, linear and weighted growth), a tutorial video and a first indicator showing whether the whole market is over- or undervalued. dated in public at the time [3]
15 September 2016New website with database and hotlist: users enter fair values, much like Wikipedia, and check each other. First list of 18 stocks that appear undervalued. dated in public at the time [3]
19 July 2017Community database with more than 100 entries, an automatic hotlist and a way to report wrong values (three reports trigger a review). dated in public at the time [3] [4]
8 May 2019Relaunch after two years of development: automatic valuation from a large database, screener, watchlist, two languages, plus a premium area for diversified portfolios. dated in public at the time [4]
4 December 2019Detailed calculator in answer to the criticism "two inputs are too few": earnings growth, profitability, revenue growth, return on equity, EBIT margin and book value now feed in, weighted by his own statistical analysis. dated in public at the time [4]
18 March 2020After criticism of data quality and cyclical stocks: smoothing by median and geometric mean, a warning for highly leveraged companies, stars for data quality, a freshness indicator. dated in public at the time [5]
2020The handbook "Die Fair Value Calculator Methode" (77 pages) documents the method and the tools: automatic fair values for more than 33,000 stocks, market analysis, sector analysis, quality check, total score, watchlist and portfolio manager. handbook 2020 [9]
24 July 2020Discounted cash flow and the PEG ratio are integrated as further valuations. dated in public at the time [6]
8 January 2021Several valuation methods are computed automatically and combined into one fair value. A video series of six lessons follows. dated in public at the time [6]
14 November 2021Star ratings from fundamentals and price trend, industry comparison for every metric, a reworked market view. dated in public at the time [6]
21 April 2022Free version: all tools and five stocks a month at no cost. Mobile optimisation follows in June 2022. dated in public at the time [6]
16 March 2024The model blend is explained openly: more than twelve methods, among them DCF, analyst estimates, peer multiples, Peter Lynch and Graham. The sentence that goes with it: "There is no single correct fair value, but there are many methods to get as close to it as possible." dated in public at the time [6]
8 September 2025AI valuation for soft factors: brand strength, management quality, competitive advantages and scalability complement the numbers. dated in public at the time [6]
28 July 2026In its tenth year, the complete rebuild: about 35,000 stocks worldwide, valuation and quality as two separate questions, a range from cautious to optimistic case, an evidence status per stock, a portfolio optimizer and a 34-year test. dated in public at the time [6] [7]
August 2026Public corrections after hints from the forum: an error with one-off losses (Amazon, Rivian) is fixed, the cap on downside potential at 80 percent is removed, the search finds stocks by name, ISIN, German WKN and ticker. dated in public at the time [7] [8]
October 2026Current state: 26 valuation models, up to 37 quality factors, about 35,000 valued stocks, an AI verdict with the main risk per stock, user comments and votes, a free academy of 16 lessons and a connection for AI assistants. own account [11]

What the critics changed

The forum was not kind, and that is the most valuable part of the record. A history in which outsiders find errors and the product changes in response cannot be invented afterwards.

YearThe objectionWhat became of it
2016The formula is a black box; proof needs a hundred stocks and more than ten years. [1]Today the methodology is published on the site, the test covers 34 years and is adjusted for companies that no longer exist.
2016Two inputs (earnings and growth) are not enough for cyclical companies and tough industries. [1]Two inputs became 26 models weighted by industry, plus a separate quality score from up to 37 factors.
2016A stock split changes the result, which must not happen. [2]Every figure is computed per share on the current share count, splits are checked and adjusted daily.
2020The best formula is useless if some of the underlying data is wrong. [5]Every stock carries an evidence status. Where the data is too thin, the fair value is withheld rather than showing a wrong number.
2020Return on equity misleads when debt is high; return on capital employed is better. [5]Balance sheet strength is a family of its own in the quality score, high leverage is scored and shown, and return on invested capital is available in the screener.
2026Growth stocks look permanently overvalued. [7]The fair value stays deliberately sober ("a yardstick, not a price target"); in return the site shows openly how much growth the price assumes, and a documented premium for quality growth was added.

What is proven and what remains our own account

The full story with every step is in the free handbook: Part IV, "The Origin" (also as PDF).

Sources

  1. [1] Wertpapier-Forum, thread "Fair Value Calculator", page 1: launch post of 21 March 2016 and first criticism. https://www.wertpapier-forum.de/topic/48870-fair-value-calculator/
  2. [2] Wertpapier-Forum, page 2: backtests March to June 2016, stock split debate. https://www.wertpapier-forum.de/topic/48870-fair-value-calculator/page/2/
  3. [3] Wertpapier-Forum, page 3: helper calculators, tutorial video, market valuation, database 2016 and 2017. https://www.wertpapier-forum.de/topic/48870-fair-value-calculator/page/3/
  4. [4] Wertpapier-Forum, page 4: relaunch of 8 May 2019, detailed calculator of 4 December 2019. https://www.wertpapier-forum.de/topic/48870-fair-value-calculator/page/4/
  5. [5] Wertpapier-Forum, page 5: criticism of data and cyclical stocks, replies January to April 2020. https://www.wertpapier-forum.de/topic/48870-fair-value-calculator/page/5/
  6. [6] Wertpapier-Forum, page 6: 2020 to July 2026 (DCF and PEG, several models, free access, AI valuation, rebuild). https://www.wertpapier-forum.de/topic/48870-fair-value-calculator/page/6/
  7. [7] Wertpapier-Forum, page 7: feedback and corrections in July and August 2026. https://www.wertpapier-forum.de/topic/48870-fair-value-calculator/page/7/
  8. [8] Wertpapier-Forum, page 8: discussion up to 27 September 2026. https://www.wertpapier-forum.de/topic/48870-fair-value-calculator/page/8/
  9. [9] Klein, Peter (2020): "Die Fair Value Calculator Methode. Wahrer Wert schlägt den Markt", handbook, 77 pages (German). https://s0c1cccdcaae15a1c.jimcontent.com/download/version/1609693918/module/9220685476/name/ebook%202020.pdf
  10. [10] wikifolio "Fair Value Calculator" by Dr. Peter Klein, created on 30 March 2016. https://www.wikifolio.com/de/de/w/wf11224488
  11. [11] fairvalue-calculator.com: methodology, data and trust, current state. https://www.fairvalue-calculator.com/methodology

All sources read again on 11 October 2026.

What we believe

Common questions about our origin

Since when has the Fair Value Calculator existed?

Since 20 March 2016. On that day fairvalue-calculator.com went online, and on 21 March 2016 the calculator was presented in public in the German Wertpapier-Forum. The post can still be read today.

Who built the Fair Value Calculator?

Dr. Peter Klein from Austria. He has studied stocks since 2004, wrote the first formulas during his studies and has developed the tool in public since 2016.

Is the Fair Value Calculator the original?

Yes, under this name: the Fair Value Calculator has carried it in public since March 2016 and has dated development steps on record for every year since. The term fair value and methods such as Graham or discounted cash flow existed before; our contribution is the product that combines many models into one figure.

How has the Fair Value Calculator developed since 2016?

From a single calculator with two inputs (2016) through database, screener and watchlist (2019) and the blend of several models (2021) to the platform of today with 26 valuation models, up to 37 quality factors and about 35,000 valued stocks.

Where is the history documented?

In the Wertpapier-Forum (thread "Fair Value Calculator", eight pages since 21 March 2016), in the 2020 handbook and in the public wikifolio of 30 March 2016. All sources are listed on this page.

Who is behind it

Dr. Peter Klein, founder of the Fair Value Calculator

Dr. Peter Klein

Founder, Graz, Austria. Dentist, and a private investor since 2004.

I built the calculator for myself first, because I wanted to know what a stock is worth before I buy it. It has been public since March 2016, and I have worked on it almost every day since.

Two expensive mistakes with leveraged products and a forgotten demo portfolio that quadrupled without my help turned me into a long-term investor by value.

The story since 2016, with sources →

The Fair Value Calculator is operated by an Austrian-registered company; the person responsible for content is Dr. Peter Klein. Contact: [email protected]. Full details in the imprint.

Free & Pro

Browsing, searching and valuing individual stocks is free and needs no sign-up. Pro (€9.90/month, first month €1) adds tools for ongoing monitoring, a watchlist with overvaluation alerts, diversification and market-valuation checks, and the full screener.

Start free → See Pro · Methodology · Risk notice