Enrichment · Passion Projects · Running

Your 5K time,
as a pace you can
hold on the track.

Choose the distance and type your time. The calculator gives your pace per mile and per kilometre, your speed, the lap time on a track, even splits and estimates for other races.

Convert a timeWhat you get

The pace calculator

The worked example is a made-up 24:45 cross-country 5K. Nothing you type leaves this browser.

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What you get

Enrichment · Passion ProjectsFree

What you finish with
Pace per mile and kilometre, speed, lap time, even splits and estimated times for the mile through the marathon. It prints as a summary and downloads as a spreadsheet.
Who it is for
Student runners, cross-country and track teams, PE classes, and families who run together.
Format
Browser calculator for a phone, tablet or computer, by touch or keyboard. Prints a summary; downloads a spreadsheet (.csv); export and import a file.
Access
Free. No account, no sign-in and nothing to install. Everything you type stays in this browser; nothing is sent to Caveat.
Where it lives
The Passion Projects space in Caveat Enrichment.
Support
Questions, a correction or a request: team@caveatacademic.com.

How to use it

  1. Choose the distance, or Other and type it.
  2. Type the finish time.
  3. Read the pace, speed and splits.
  4. Use the estimates to set goals for a longer race.
  5. Print the splits for a wristband or a training log.

Convert a time

How pace is worked out

Time over distance, and one well-known estimate.

The worked example: a 24:45 5KTime24:45= 1,485 s÷ 5 km4:57 /km1,485 ÷ 5÷ 3.107 mi7:58 /mi1,485 ÷ (5,000 ÷ 1,609.344)10K estimate51:361,485 × 2^1.06The worked example: a 24:45 5KTime24:45= 1,485 s÷ 5 km4:57 /km1,485 ÷ 5÷ 3.107 mi7:58 /mi1,485 ÷ (5,000 ÷ 1,609.344)10K estimate51:361,485 × 2^1.06
Pace is time per unit of distance, the reverse of speed. Riegel’s exponent of 1.06 adds a little slowing for each doubling of distance.

The arithmetic

Pace is the finish time divided by the distance; speed is the distance divided by the time. A mile is exactly 1.609344 km. Even splits divide the time in proportion to the distance covered. A 400 m lap is the time for 400 m at the same pace.

The race estimates

Pete Riegel's 1981 formula, time₂ = time₁ × (distance₂ ÷ distance₁)^1.06, fits many runners from about 1.5 km to the marathon when they have trained for the longer race. It is a rough guide: heat, hills and training change real results, and newer runners often slow more in the marathon.

Sources

  1. Riegel, P. S. (1981). Athletic records and human endurance. American Scientist 69(3), 285 to 290.
  2. World Athletics. Competition and Technical Rules: road race distances (half marathon 21.0975 km, marathon 42.195 km) (worldathletics.org).
  3. National Institute of Standards and Technology. Handbook 44, appendix C: the international mile, 1.609344 km (nist.gov).
  4. Centers for Disease Control and Prevention. Physical activity guidelines for children, teens and adults (cdc.gov/physical-activity).

The worked example is made up. Estimates are guides, not predictions. Your times stay in this browser. Support: team@caveatacademic.com.