How this calculator works
Age grading divides the standard time for your age and sex by your actual time. The standards are the USA Track and Field 2025 road age standards, built for 5 km, 10 km, half marathon and marathon and published for ages 5 to 100. A grade of 100 percent means you matched the standard; lower grades are slower, and a grade above 100 percent is faster than the standard. The open-equivalent time is what your performance would be worth at the open standard, which makes a 60-year-old 5 km comparable with an open 5 km. The comparison at another age or sex scales the same grade to that group.
Formula
Age grade = age standard time / your time. Open-equivalent time = your time x open standard / age standard. Equivalent time at another age or sex = your time x other standard / your age standard.
Worked example
A 35-year-old man runs 5 km in 20:00, or 1,200 seconds. The male 5 km standard at 35 is 783 seconds, so the age grade is 783 / 1,200 = 65.3 percent. The open standard is 769 seconds, so the open-equivalent time is 1,200 x 769 / 783 = 1,179 seconds, or 19:39.
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Frequently asked questions
What counts as a good age grade?
The usual bands are above 90 percent world class, above 80 percent national, above 70 percent regional and above 60 percent local. Most recreational runners land between 50 and 70 percent.
Which standards are used?
The USATF 2025 road tables for 5 km, 10 km, half marathon and marathon, covering ages 5 to 100. They are separate from the track and field age factors used for other distances.
Why is the equivalent time not simply my time?
The standard already accounts for age and sex. Dividing by the standard and multiplying by the open standard converts the performance to the open level, so results from different ages can be compared directly.
Are the standards reliable at very young ages?
The youngest ages are based on sparse data and can jump between neighbouring ages. Treat grades under about age 10 as indicative only and use the same table for both athletes when comparing.