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RUNNERS LAB

1K Repeats
Calculator

Session clock for 1000m repeats at a target pace with rest.

Last reviewed 19 August 2026

Five × 1 km at 4:00/km with 90 seconds rest is 4:00 per rep, 20:00 of running, 6:00 of rest, and 5.0 km of work. A kilometre is 2.5 laps of 400 m.

1K pace (min/km)
SEC

Session clock

24:00

  • 1K 4:00
  • Work 5.00 km
  • Each 4:00 /km

What this result means

1K repeats sit on the track or the road. This page locks work distance at 1.000 km. Pace, reps, rest. The interval workout calculator is the generic version.

1500m pace is a race clock, not a repeat set. Training-pace VDOT interval bands can suggest the pace you type here.

6 × 1K at 3:50/km with 2:00 rest: 3:50 each, work 23:00, rest 10:00, session 33:00, work 6 km.

Cruise 1Ks at threshold are slower than 400m repeat pace. Enter the pace you mean.

Calculation method

Work time = 1 km × seconds per km. Session totals use rest × (reps − 1).

Exact arithmetic.

A “1K” on a short GPS loop is not 1000 m. A track 1000 m is 2.5 laps from a measured start.

Full methodology →

Frequently asked questions

How many laps is a 1K?

Two and a half laps of 400 m.

What is 5 × 1K at 4:00/km with 90s rest?

4:00 each, 20:00 work, 6:00 rest, 26:00 session, 5 km work.

Can I use mile pace?

Yes. Switch the header to miles and enter min/mile. Internally the work is still 1.000 km.

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