What age grading is
Age grading converts a running performance into a single percentage that can be compared fairly across ages, sexes, and distances. It answers the question "how good is this time, really?" for a runner whose raw finish time is shaped by their age and sex. A 40:00 10K might be an ordinary result for a 25-year-old man and an outstanding one for a 68-year-old woman — age grading puts both on the same 0-100% scale so they can be ranked side by side.
The system is maintained by World Masters Athletics (WMA), which publishes age-grading tables (the widely used sets were compiled by Alan Jones and Rex Harvey). For each distance, age, and sex, the tables give a standard time — the theoretical best a runner of that exact age and sex could be expected to run. Your age grade is simply how close you came to that standard.
The formula
The calculation is a single division:
Age grade (%) = (age-and-sex standard time ÷ your finish time) × 100
Because the standard time is on top, a faster (smaller) finish time gives a higher percentage. If your time exactly matches the standard you score 100%; if you run half as fast (double the time) you score 50%. For example, a standard time of 13:00 (780 s) against a finish time of 21:30 (1290 s) gives 780 ÷ 1290 × 100 = 60.5%.
The one value you must look up is the standard time for your age, sex, and distance. It is the WMA open-class world standard for the distance adjusted by an age factor: standard time = open-class standard ÷ age factor, where the age factor is 1.0 in the peak-performance years (roughly the mid-20s to early 30s) and falls below 1.0 as age rises. Enter that standard time and your finish time above and the calculator returns the grade.
What the percentage means
- 100% — equal to the age-graded world record for your age and sex.
- 90%+ — world-class.
- 80-90% — national-class.
- 70-80% — regional-class; a strong, well-trained club runner.
- 60-70% — local-class.
- Below 60% — recreational; the range most casual runners occupy.
Why runners use it
Age grading lets a masters runner see genuine improvement even as raw times slow with age: holding an 80% grade at 55 that you had at 45 means you are still performing at the same relative level despite a slower clock. It also lets a race compare a 5K to a marathon result, or a woman's time to a man's, on equal footing — which is why parkrun and many masters competitions publish age-graded results alongside finish times.