parkrun gives every participant an age grading score, used to benchmark performance relative to age.
Below you’ll find an application to calculate your parkrun age grading online, accurate to within 0.03%–0.36%. I believe this is the only online tool that returns data this precise, since parkrun uses proprietary tables that differ from the official WMA/USATF Road 2025 tables (public data, CC0 license).
To correct for these differences, I used Claude AI to reverse-engineer the exact formula, feeding the model with several thousand real data points from recent parkrun events around the world.
Alongside the percentage, the calculator also shows a label placing your performance into a class, based on the standard scale used in age grading (the same one underlying the WMA systems that parkrun itself is built on):
| Age Grading | Class |
|---|---|
| 100% and above | World Record |
| 90% to 99.99% | World Class |
| 80% to 89.99% | National Class |
| 70% to 79.99% | Regional Class |
| 60% to 69.99% | Local Class |
| Below 60% | Recreational |
In addition to the age grading percentage, the calculator also provides 3 further useful indicators.
Age-Graded Time: your age-“corrected” time — the time you’d have run if you were in the peak performance age range (roughly 19-26). The closer it is to the Open Class Standard, the higher the level of your performance.
Age Factor: the coefficient (between 0 and 1) accounting for how much performance naturally declines, or hasn’t yet peaked, depending on age. A factor close to 1 means you’re in the peak-performance age range.
Open Class Standard (5K): the absolute reference time over 5K — the official world record for the open category (no age distinction) — used as the benchmark for calculating the Age Grading percentage.
Calculate your Age Grading
Compare your performance with the world standard for your age and sex.
- Age-graded time
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- Age factor
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- Open-class standard (5 km)
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Calculation based on real parkrun age categories, calibrated on 814 real race results and supplemented with the WMA/USATF Road 2025 tables for the few categories with insufficient data. Small deviations from the value shown by parkrun are still possible.