Interval session pace calculator

This gives a target pace band for your intervals from a recent race, the way coaches set them.

Your details

Your interval pace

4:51

per kilometre, the middle of your range

Per kilometre4:45 to 4:57
Per mile7:39 to 7:59
Your VDOT score38.3
400 m reps1:54 to 1:59
1 km reps4:45 to 4:57

Intervals are hard but controlled, about the pace you could hold for 10 to 12 minutes in a race. Keep reps to 3 to 5 minutes, jog as long again between, and stop the set while your form is still good.

The working

From a 25 minute 5K

A 25:00 5K is a VDOT of 38.3 in the Daniels and Gilbert equations. Intervals sit at 95 to 100% of that, which gives 4:45 to 4:57 per kilometre, or 1:54 to 1:59 for each 400 m rep.

A good session

Shape of the workout

Warm up 10 to 15 minutes easy, plus a few strides
4 to 6 reps of 3 to 4 minutes at interval pace
Jog recovery about as long as each rep
Cool down 10 minutes easy

How often

Less is more

One interval session a week is plenty for most club runners, with mostly easy running around it. Total hard running in a session should stay around 8% of your weekly distance or under 10 km.

Read with care

What this cannot tell you

Old racesUse a race from the last 6 weeks or so.
Heat and hillsGo by effort if conditions are tough.
Heart conditionsAsk your GP or cardiac team before hard efforts.

Questions

Common questions

How fast should my intervals be?

About the pace you could race for 10 to 12 minutes.

What is VDOT?

A running fitness score from Jack Daniels, worked out from a race time.

How much rest between intervals?

Roughly equal to the rep, as an easy jog.

Sources

Last checked 21 October 2026. Spotted something wrong? Tell us and we will fix it.

Before you push on

New to exercise, or got a heart, lung or joint condition? Have a word with your GP or practice nurse first. Stop and get help if you feel chest pain, faintness or unusual breathlessness, and call 999 if it is severe.