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RUNNERS LAB

Reverse Age
Grading

Find the clock time that hits a target age-grade percentage.

Last reviewed 19 August 2026

Reverse age grading starts from a percent, not a clock. If you want 70% on a 5K at 40, the tool returns the time that percent implies. It inverts the same interpolated WMA 2015 factors as the forward age-grading page.

Distance

YRS
%

Comparison category

Required clock time

19:34

  • Regional class
  • Open standard 12:49

What this result means

Forward age grading asks how good a time is. Reverse asks what time you need for a target percent. Enter age, comparison category, distance, and a target such as 70% (often called strong regional) or 80% (national class as a convention).

The output is still an estimate from a table, not a qualifying standard. Hitting that clock on a downhill course is not the same as hitting it on a certified flat 5K.

A 40-year-old aiming at 70% on 5K gets a slower clock than a 25-year-old aiming at 70%, because the elite standard slows with age. The same 70% on a marathon is a different conversation from 70% on a 5K.

If you already have a time, use the age-grading calculator. If you want a friendly band name for a time you already ran, use How Good Is My Running Time?

Calculation method

Clock = open standard ÷ (factor × target percent / 100). Same factors and open standards as forward age grading. Bands use the same 90/80/70/60 cut-points.

Cite: WMA 2015 interpolated subset on this site.

Target percents above what you can train for are just numbers. The tool will still compute 95%. That does not make 95% a sensible next 5K.

Full methodology →

Frequently asked questions

What time is 70% age grade for my 5K?

It depends on age and category. Enter those plus 70% on this page. 70% is a conventional “regional” label, not an award.

Can I enter an open-class time instead of a percent?

This page inverts percent. The forward age-grading tool shows the open standard beside your result.

Is this a qualifying time?

No. It is a table lookup inverted. Federations publish their own standards.

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