What this result means
Track sessions are often written in lap times while road runners think in min/km. This calculator converts either way on a 400 m oval and can multiply by a number of laps. It does not add rest; use the interval or repeats tools for that.
A mile is four laps plus 9.3 m — use the mile track calculator for that extra bit. This page is the pure 400 m identity.
5:00/km is 2:00 per 400 m. 4:00/km is 1:36. A 75-second lap is 3:07/km. Ten laps at 80 seconds is 13:20 of work.
If your watch shows 8:03/mile, that is also 5:00/km and a 2:00 lap. The header unit toggle switches the pace field.
Calculation method
Lap time = pace per km × 0.4. Pace per km = lap time ÷ 0.4. Total time = lap time × laps. Rounding to the nearest second on display.
Exact arithmetic. Not a start-line stagger model and not a lane-2 adjustment.
Lane 2 is longer than lane 1. Indoor tracks are often 200 m. This tool assumes 400 m outdoors, lane 1.
Frequently asked questions
What is 5:00/km in 400m laps?
Two minutes per lap. Enter 5:00/km or a 2:00 lap to convert either way.
Does this include rest?
No. Add rest on the repeats or interval workout calculators.
How many laps is 5K?
12.5 laps of 400 m. This page totals whole laps you enter; for 5K pace use the 5K tool.
Should I use the 400m split calculator instead?
Use that page when you have a 400 m goal time and want even 200 m splits. Use this page to convert pace to lap time, or a lap time to pace, and optionally multiply by n laps.