The short answer
Age grading converts a performance into a percentage of the age-adjusted world standard. The formula is age standard divided by your time, times 100. The WMA tables supply an age factor for every age, sex, and event. Roughly: 60 percent is local class, 70 regional, 80 national, 90 world class, 100 world-record level.
Key takeaways
- Age-grade percentage = age standard / your time x 100 for running events
- The age standard comes from an open-class standard divided by a WMA age factor
- WMA revised the factors in 2023 using millions of performances; that is the current edition
- Tiers: 90 percent world class, 80 national, 70 regional, 60 local, 100 near world-record
- Age grading lets a 70-year-old and a 35-year-old be compared on one scale
What age grading actually is
Age grading is a handicap system. It takes a raw performance, a time or a distance, and corrects it for the athlete's age and sex, then expresses the result as a percentage of the world standard for that age. The point is comparison. Without it, a 12.0 hundred at 68 and a 10.8 at 40 are just two numbers. Age-graded, they become two percentages you can rank head to head. A 100 percent score means you matched the world-record-level standard for your exact age.
Built on millions of results
The 2023 WMA age-grading tables were rebuilt using over 2.8 million additional performances, including lifetime histories, making the current factors the most accurate model of age-related decline yet published.
Source: World Masters Athletics, Age Grading Leaps Forward (2023)
The formula, step by step
For a running event, where a lower time is better, the calculation is short:
- Age-grade % = age standard / your time x 100
- Age standard = open-class standard / age factor
- Age-graded time = your time x age factor (the equivalent open-age time)
The open-class standard is a fixed reference time for the event, close to the open world record. The age factor is a number at or below 1 that the WMA tables assign to every single age, sex, and event. You look up the factor, divide the open standard by it to get the age standard, then divide that by your time. For field events, where bigger is better, the ratio flips: age-grade % is your distance divided by the age standard, times 100.
A worked example
Take a 60-year-old man running the 100m in 13.50. The age-adjusted world standard for a 60-year-old is close to the M60 world record of 11.70. Divide that standard by your time: 11.70 / 13.50 = 0.867, so about 86.7 percent, a strong national-class run. The same 13.50 at age 40 would grade far lower, because the age standard at 40 is much faster. That is the whole trick: the older you are, the more forgiving the standard, in exact proportion to how much humans actually slow down.
Where the factors come from
The tables were originally built by Alan Jones and Rex Harvey, whose male factors were completed in 2004 and female factors in 2006. WMA has revised them repeatedly: 1989, 1991, 1994, 2006, 2010, 2015, and the current 2023 edition. Each revision folds in new world bests and a larger pool of results, so the decline curve tracks reality more tightly. The current factors live in the WMA 2023 Age Factors document, and the open-source Alan Jones tables are published on GitHub under a CC0 public-domain license.
Use the right edition
An age-grade score is only meaningful next to scores from the same table edition. A percentage from the 2015 tables will not match the 2023 tables for the same performance. Always confirm which edition a calculator uses.
Source: World Masters Athletics 2023 Age Factors
What the percentage tiers mean
WMA and USATF publish the same plain-language bands. They are the fastest way to read any age-grade score.
Age-grade performance tiers
The standard WMA and USATF interpretation of an age-graded percentage.
| Age grade | Level |
|---|---|
| 100% | Approximate world-record level |
| 90% and up | World class |
| 80% and up | National class |
| 70% and up | Regional class |
| 60% and up | Local class |
| Below 60% | Developing or recreational |
These tiers are consistent across every event and age, which is the point. An 82 percent shot put at 55 and an 82 percent 800m at 35 are both, by definition, national-class efforts for their age. For real performance examples at each tier, see what is a good age-graded score.
How to calculate yours
- Find a calculator that states it uses the WMA 2023 tables, such as the Howard Grubb track and field calculator.
- Enter your exact age on the day of the performance, your sex, the event, and your mark.
- Read the percentage and place it on the tier table above.
- Recompute as you age, since the standard shifts every birthday.
Why masters athletes lean on it
Age grading does two things a stopwatch cannot. It lets a club rank a mixed-age field fairly, and it gives an individual a single number to chase as the raw times inevitably slow. A masters athlete whose 100m drifts from 12.8 to 13.1 over three years might still be climbing in age-grade percentage, which means they are actually improving relative to the curve. That is a far healthier target than a clock that only ever moves the wrong way. Once you know your number, the cheapest points left are technical, which is where frame-by-frame video earns its keep.