Useful examples
- Enter 2:00:00 to evaluate a common half marathon milestone.
- Enter 1:45:00 to compare a stronger recreational age-group result.
- Use the adjusted time when comparing across age groups, not only the raw clock time.
Half marathon calculator
Half Marathon Age-Grading Calculator
Use this half marathon age-grading calculator to understand a 13.1-mile result in age-group context. The calculator estimates pace, age-graded percentage and open-age equivalent time from sourced road standards.
Age-graded calculator
Enter one race result
Results use sourced 2025 road-running age standards and are informational estimates, not official rankings.
Age-graded result
Raw finish time55:00
Pace per km2:36
Pace per mile4:12
Age-graded percentage125.8%
Age-adjusted equivalent45:44
A 57-year-old male running Half marathon in 55:00 is age-adjusted to approximately 45:44. That means the performance is comparable to an open-age runner completing Half marathon in about 45:44.
2025 road age standards from Alan Lytton Jones' Age-Grade-Tables project (CC0-1.0); exact age 57, age standard 1:09:10, open standard 57:31, factor 1.203.Uses CC0 road-running age standards. Results are informational age-graded estimates, not official WMA rankings. Source files: 2025 Files/MaleRoadStd2025.xlsx, 2025 Files/FemaleRoadStd2025.xlsx at commit 4aac6737cb9f216c90a0a610355667cd3d921c61.Read the methodology
Why half marathon age grading is useful
The half marathon rewards endurance, pacing and durability. Age can affect recovery and training consistency, so raw finish time alone often misses part of the story.
Age grading helps you compare a recent half marathon with a past result, another age-group runner or a goal time without pretending that course, weather and training history do not matter.
Good uses for this page
- Checking whether a half marathon goal still represents the right challenge.
- Comparing a half marathon result with 10K or marathon progress.
- Adding context when raw pace slows but endurance remains strong.
Keep learning
Compare the result with useful context
FAQ
Half marathon calculator FAQs
Quick answers for using this distance-specific calculator sensibly.
What does the half marathon result show?
It shows your pace, age-graded percentage and an age-adjusted equivalent time for the half marathon distance.
Can age grading explain course difficulty?
No. Age grading adds age and gender context, but it does not adjust for hills, wind, heat, pacing mistakes or training history.
Should I use the adjusted time as a race target?
Use it as context, not as a promise. A good goal should also consider training, recovery, course profile and recent race evidence.