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RUNNERS LAB

800m Repeats
Calculator

Session clock for 800m repeats at a target pace with rest.

Last reviewed 19 August 2026

Six × 800 m at 4:00/km with 2:00 rest is 3:12 per rep and 3.2 km of work. Yasso 800s set the 800 time from a marathon goal instead of from a pace you type. Use that page if you want the heuristic.

800m pace (min/km)
SEC

Session clock

24:12

  • 800m 3:12
  • Work 4.80 km
  • Each 4:00 /km

What this result means

800m repeats are a classic VO2 session. This calculator uses a pace you choose, a rep count, and rest. It does not pull 800 times from a marathon clock.

The 800m pace calculator is one two-lap time trial. This page is the set with rest.

5 × 800 at 3:45/km with 2:30 rest: each 3:00, work 15:00, rest 10:00, session 25:00, work 4.0 km.

Yasso for a 3:10 marathon would target 3:10 800s regardless of the pace field on this page. Different tools.

Calculation method

Work time = 0.8 × seconds per km. Totals as for any interval session: rest × (reps − 1).

Exact arithmetic.

Track 800s on a hot day need more rest than the number you typed if you typed a winter rest. The tool will not argue.

Full methodology →

Frequently asked questions

Is this Yasso 800s?

No. Yasso maps marathon H:MM to 800 MM:SS. This page uses a pace you enter.

How much rest should I take?

Coaching call. 1:1 to 2:00 is common. The work/recovery tool converts a ratio into seconds.

What is 6 × 800 at 4:00/km?

3:12 each, 3.2 km of work, plus whatever rest you enter between.

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