Purdy Points Running Calculator

Score any race in Purdy points and compare distances fairly.

How it is calculated

Each distance has a standard time in the tool (5K 13:17, 10K 27:39, half marathon 1:02:00, marathon 2:08:34, among others) that is worth exactly 950 points. With Ts the standard time in seconds, T your time in seconds and d the distance in metres: v = d ÷ Ts, K = 0.0654 − 0.00258 × v, A = 85 ÷ K, B = 1 − 950 ÷ A, and points = A × (Ts ÷ T − B). The tool also shows your average speed in m/s, your percentage of the standard (Ts ÷ T), a 5K time worth the same points, and a label from Recreational up to World record class. Distances are 800, 1500, mile, 3000, 5K, 10K, half and marathon. Time is in decimal minutes (22 means 22:00), up to 600. A time faster than 95 % of the world record for the distance gives no result. One standard table is used, with no sex or age input.

Worked example

A 5K in 22 minutes. The standard 5K time is 796.6 s and yours is 1,320 s. The standard speed is 5,000 ÷ 796.6 = 6.28 m/s, so K = 0.0654 − 0.00258 × 6.28 = 0.0492 and A = 85 ÷ 0.0492 ≈ 1,727. B = 1 − 950 ÷ 1,727 = 0.450. Points = 1,727 × (796.6 ÷ 1,320 − 0.450) = 265. That is 60.3% of the standard, labelled Recreational, your average speed is 3.79 m/s, and the 5K equivalent is naturally the same 22:00.

Try this example →

Common mistakes

  • Typing 22.30 for 22 minutes 30 seconds. The field is decimal minutes, so 22.30 is 22 minutes 18 seconds (251 points); 22.5 gives 242.
  • Selecting a different distance from the one you raced. Points differ a lot between 5K and 10K for the same number of minutes, and an unrecognised distance silently falls back to 5K.
  • Expecting 1000 points to be the elite mark. Here 950 is the level of the standard table, and higher scores mean faster than that standard.
  • Comparing these points with another Purdy table. This tool uses its own standard times, one set for all runners, so numbers will not match a table with age or sex columns.
  • Entering a time that is not a realistic race result. Anything faster than 95 % of the world record, such as a 5K in 5 minutes, shows no result.

About this calculator

The Purdy Points system, devised by Gardner and Purdy in 1970, scores a race performance by comparing your time against a ‘standard’ time set for that distance, producing a single comparable number — similar in spirit to age-grading, but anchored to sport-wide performance standards instead of age. The standard is the same for every runner, so there is no separate sex-specific scale.

Coaches, running statisticians and club scoring systems — grand prix series that rank members across a season of different races, for instance — use Purdy points to compare performances fairly across wildly different distances, so a strong 5K effort can be weighed directly against a strong marathon effort.

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