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Running pace calculator

Enter a distance and a time to see your pace per mile and per kilometre, your speed, and what that pace means for a 5K, 10K, half marathon or marathon.

 
Time
h min s
Pace
—
Pace per km
Pace per mile
Speed
Finish time at this pace
5K
10K
Half marathon
Marathon

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How to use the pace calculator

  1. Enter the distance and choose miles or kilometres, or tap a race distance.
  2. Enter your time in hours, minutes and seconds.
  3. You get your pace per mile and per km, your speed, and finish times at that pace.

The formulas

Pace = time ÷ distance

Speed (km/h) = distance (km) ÷ time (hours)

Worked example

A 10K in 50:00 is a pace of 5:00 per km or 8:03 per mile – a speed of 12 km/h (7.46 mph). Held for longer races, that pace gives a 25:00 5K, a 1:45:29 half marathon and a 3:30:59 marathon.

Realistic race predictions

Most runners slow down as distance grows. Peter Riegel’s formula, T₂ = T₁ × (D₂ ÷ D₁)1.06, is a popular way to predict longer races: from a 50-minute 10K it predicts about 1:50:19 for a half marathon and 3:50:01 for a marathon – slower than the even-pace times above. Use the even-pace table as a goal and the Riegel time as a realistic check.

Training plans often use several paces: easy runs 60–90 seconds per km slower than race pace, tempo runs close to your 10K–half-marathon pace.

Frequently asked questions

What is a good running pace?
It depends on age and experience. Many recreational runners run easy miles at 9–12 minutes per mile (5:30–7:30 per km). Comparing yourself with your own past times is more useful than any average.
How do I convert pace per km to pace per mile?
Multiply by 1.609. A 5:00 per km pace is 5 × 1.609 = 8.05 minutes, or about 8:03 per mile.
What pace do I need for a sub-4-hour marathon?
About 5:41 per km or 9:09 per mile, held for the whole 42.195 km.

Last reviewed: November 13, 2026

Results are estimates for general information only and are not financial, tax, medical or legal advice. Check important figures with a qualified professional.