PorvairCHIX:PRVL -2.17%95 Graham Number is £4.05 as of May. 2026, which is 100% below its 10-year median of 2.85. GuruFocus rates CHIX:PRVL with a GF Score™ of 95/100 and a GF Value™ of £7.60 (Fairly Valued). The stock has 3 warning signs investors should review. Among 2,197 Industrial Products companies, Porvair ranks worse than 54.67% on this metric.
Graham Number is a figure that measures a stock's fundamental value by taking into account the company's earnings per share and book value per share. The Graham number is the upper bound of the price range that a defensive investor should pay for the stock. According to the theory, any stock price below the Graham number is considered undervalued, and thus worth investing in.
As of today (2026-07-09), the stock price of Porvair is £8.12. Porvair's graham number for the quarter that ended in May. 2026 was £4.05. Therefore, Porvair's Price to Graham Number ratio for today is 2.01.
The historical rank and industry rank for Porvair's Graham Number or its related term are showing as below:
CHIX:PRVl'
s Price-to-Graham-Number Range Over the Past 10 Years
Min: 1.81 Med: 2.85 Max: 5.56
Current: 2.01
During the past 13 years, the highest Price to Graham Number ratio of Porvair was 5.56. The lowest was 1.81. And the median was 2.85.
CHIX:PRVl's Price-to-Graham-Number is ranked worse than 54.67% of 2197
companies
in the Industrial Products industry
Industry Median: 1.75
vs CHIX:PRVl: 2.01
Graham Number is a combination of asset valuation and earnings power valuation. It is a very conservative way of valuing a stock.
Porvair (CHIX:PRVl) Graham Number Explanation
Ben Graham actually did not publish a formula like this. But he wrote in The Intelligent Investor (1948 version) regarding to the criteria for purchases:
Current price should not be more than 15 times average earnings of the past three years.
Current price should not be more than 1.5 times the book value last reported. However, a multiplier of earnings below 15 could justify a correspondingly higher multiplier of assets. As a rule of thumb we suggest that the product of the multiplier times the ratio of price to book value should not exceed 22.5. (This figure corresponds to 15 times earnings and 1.5 times book value. It would admit an issue selling at only 9 times earnings and 2.5 times asset value, etc.)
Unlike valuation methods such as DCF or Discounted Earnings, the Graham number does not take growth into the valuation. Unlike the valuation methods based on book value alone, it takes into account the earnings power. Therefore, the Graham Number is a combination of asset valuation and earnings power valuation.
In general, the Graham number is a very conservative way of valuing a stock. It cannot be applied to companies with negative book values.
Porvair's Price to Graham number Ratio for today is calculated as
Price to Graham number
=
Share Price (Today)
/
Graham number (Q: May. 2026 )
=
8.12
/
4.05
=
2.01
* For Operating Data section: All numbers are indicated by the unit behind each term and all currency related amount are in USD. * For other sections: All numbers are in millions except for per share data, ratio, and percentage. All currency related amount are indicated in the company's associated stock exchange currency.
Be Aware
Please keep these in mind:
1. Graham Number does not take growth into account. Therefore it underestimates the values of the companies that have good earnings growth. We feel that if the earnings per share grows more than 10% a year, Graham Number underestimates the value.
2. Graham Number punishes the companies that have temporarily low earnings. Therefore, an average of earnings makes more sense in the calculation of Graham Number.
3. Graham Numbers underestimates companies that are light with book.
Porvair Graham Number Related Terms
Porvair Graham Number Historical Data
* Premium members only.
The historical data trend for Porvair's Graham Number can be seen below:
* For Operating Data section: All numbers are indicated by the unit behind each term and all currency related amount are in USD. * For other sections: All numbers are in millions except for per share data, ratio, and percentage. All currency related amount are indicated in the company's associated stock exchange currency.
CHIX:PRVL vs VLTO, ZWS, CECO: Graham Number Comparison
For the Pollution & Treatment Controls subindustry, Porvair's Price-to-Graham-Number, along with its competitors' market caps and Price-to-Graham-Number data, can be viewed below:
* Competitive companies are chosen from companies within the same industry, with headquarter located in same country, with closest market capitalization; x-axis shows the market cap, and y-axis shows the term value; the bigger the dot, the larger the market cap. Note that "N/A" values will not show up in the chart.
Porvair Price-to-Graham-Number vs Industrial Products Industry
For the Industrial Products industry and Industrials sector, Porvair's Price-to-Graham-Number distribution charts can be found below:
* The bar in red indicates where Porvair's Price-to-Graham-Number falls into.
* For Operating Data section: All numbers are indicated by the unit behind each term and all currency related amount are in USD. * For other sections: All numbers are in millions except for per share data, ratio, and percentage. All currency related amount are indicated in the company's associated stock exchange currency.
Porvair (CHIX:PRVL) has a Graham Number of £4.05 as of May. 2026. The Graham Number values a company based on its per-share earnings and book value. View historical data on Porvair and its competitors. This is 42% above median its historical median of 2.85. Over the past decade, Porvair's Graham Number has ranged from 1.81 to 5.56. According to the industry distribution chart, Porvair ranks #1201 out of 2197 companies in the Industrial Products industry, placing it in the top 54.7%.
Is Porvair's Graham Number too high?
Porvair's current Graham Number of £4.05 is 42% above median its 10-year median of 2.85. Over the past 10 years, this metric has ranged from a low of 1.81 to a high of 5.56. Based on the distribution chart, Porvair ranks #1201 out of 2197 companies in the Industrial Products industry, which is below the industry midpoint. Overall, Porvair has a GF Score™ of 95/100 and is considered Fairly Valued, reflecting its overall financial health beyond just this single metric.
How does Porvair's Graham Number compare to VLTO and ZWS?
According to the Industrial Products industry distribution chart, Porvair ranks #1201 out of 2197 companies for Graham Number. This places Porvair in the lower half of its industry. The industry median Graham Number is 1.75. Historically, Porvair's own Graham Number has ranged from 1.81 to 5.56 over the past decade. See the competitive comparison table and distribution chart on this page for a detailed peer-by-peer breakdown.
What is a good Graham Number for an Industrial Products company?
The median Graham Number among Industrial Products companies is 1.75, based on 2,197 companies in the industry. Companies in the top quartile (top 25%) have a Graham Number significantly above this median, while those in the bottom quartile fall well below. However, Graham Number should not be evaluated in isolation — investors should consider it alongside profitability, growth, and financial strength metrics. Use the industry distribution chart on this page to see where any company falls relative to its peers.
What does a high Graham Number mean?
A high Graham Number can signal that a stock is expensive relative to its fundamentals. The Graham Number values a company based on its per-share earnings and book value. View historical data on Porvair and its competitors. For the Industrial Products industry, the median Graham Number is 1.75 — values significantly above this may indicate overvaluation, while values below may suggest a bargain or underlying issues. Porvair's current Graham Number is £4.05, which is 42% above median its own 10-year median of 2.85. However, context matters — high-growth companies often justify higher valuations. Always evaluate alongside other metrics like GF Score™ and GF Value™.
Is Porvair stock overvalued right now?
Based on GuruFocus' analysis, Porvair (CHIX:PRVL) is currently considered Fairly Valued. The stock's GF Value™ is £7.60, compared to a current price of £8.12 — trading 6.8% above its estimated fair value. The current Graham Number is £4.05, which is 42% above median its 10-year median of 2.85. Porvair's overall GF Score™ is 95/100 with 3 warning signs to review. Investors should evaluate multiple metrics — including profitability, growth, and financial strength — before making a decision.
How is Graham Number calculated?
Graham Number is calculated from a company's financial statements. For Porvair (CHIX:PRVL), the current Graham Number is £4.05 as of May. 2026. GuruFocus calculates this using data sourced from SEC filings and annual reports. See the calculation section and 30-year financial data on this page for the full breakdown.
Is Porvair (CHIX:PRVL) Overvalued in 2026?
Based on GuruFocus' analysis, Porvair stock appears to be overvalued.
The current stock price of £8.12 is trading 6.8% above its estimated GF Value™ of £7.60.
GuruFocus considers Porvair to be Fairly Valued.
Key valuation signals for CHIX:PRVL:
Graham Number: £4.05 (42% above median its 10-year median of 2.85)
GF Value™: £7.60 vs. price of £8.12 (6.8% above fair value)
No single metric tells the full story. See the CHIX:PRVL stock analysis page for a complete view including 30-year financials, guru trades, and insider activity.
Porvair PLC is an environmental treatment control company. It develops filtration solutions to be used by various types of industries. The company caters to its clients through three divisions: Aerospace and Industrial, Laboratory, and Metal Melt Quality. The Aerospace and Industrial Division is a key revenue generator, principally serving the aviation, energy, and industrial markets. Laboratory Division principally serving the bioscience and environmental laboratory instrument and consumables market. Metal Melt Quality Division principally serves the world aluminium, North American Free Trade Agreement (NAFTA), iron foundry, and superalloys markets. The company generates the majority of its manufacturing revenue from sales in the United States.
95GF Score
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