Track Workout Pace Calculator: Interval Splits
Interval repetitions are run faster than race pace and measured in meters, not kilometers — which makes the split hard to compare with anything. Enter the distance in kilometers (400 m is 0.4) and the time of the repetition to get the pace it represents.
Your pace
5:00/km
Equals 12.0 km/h.
How we got this number
Pace = time ÷ distance = 25min ÷ 5 km = 5:00/km
Worked example: a 400 in 1:30
Pace = 90 seconds ÷ 0.4 km = 3:45/km, which is 16 km/h and 6:02 per mile.
Set that against a 25-minute 5K, run at 5:00/km. The repetition is 75 seconds per kilometer faster — a gear nobody holds for 3.1 miles. That gap is not an error in the workout; it is the workout.
The standard distances and what they convert to
World Athletics defines the 400 as one lap of a standard outdoor track (or two laps of a 200-meter indoor track), which is why every interval menu is built from multiples of 400.
| Repetition | Split | Pace (min/km) | Pace (min/mile) | Speed |
|---|---|---|---|---|
| 200 m | 0:40 | 3:20 | 5:22 | 18.0 km/h |
| 400 m | 1:30 | 3:45 | 6:02 | 16.0 km/h |
| 400 m | 1:15 | 3:08 | 5:02 | 19.2 km/h |
| 800 m | 3:00 | 3:45 | 6:02 | 16.0 km/h |
| 1000 m | 4:00 | 4:00 | 6:26 | 15.0 km/h |
| 1600 m | 6:24 | 4:00 | 6:26 | 15.0 km/h |
Rows 2 and 4 carry the useful lesson: a 400 in 1:30 and an 800 in 3:00 are the same pace and nowhere near the same workout. Pace describes the speed, never the cost.
The 1600-meter problem, in nine meters
A mile is 1609.344 meters exactly, per NIST. Four laps of a modern 400-meter track come to 1600, leaving you 9.344 meters short. At 6-minute mile pace you are covering 4.4704 m/s, so those 9.344 meters are about 2.1 seconds — and the reason a 1600 m time is not a mile PR.
The confusion has a history. American tracks built before metrication measured 440 yards per lap, and since a yard is 0.9144 m exactly, that is 402.336 meters — four of those laps make 1609.34 meters, an actual mile. “Four laps is a mile” was true, on a track that no longer gets built. On today’s ovals, a mile is 4.02 laps: the extra 9 meters are the reason races start a few strides back from the common finish line.
Where the interval pace goes
Repetition pace only means something next to a race target. Compare it with the 5K pace calculator or the 10K pace calculator to see how far above goal pace you are working, and use the running pace calculator for anything measured in kilometers rather than laps.
Doing intervals indoors instead? The treadmill speed to pace converter turns the console number into the same figure, so a 400 m repetition on a belt can be set at the right speed rather than guessed.
Frequently asked questions
How do I calculate pace for a 400 meter interval?
Divide the split by the distance, same as any pace. A 400 in 1:30 is 90 seconds ÷ 0.4 km = 225 seconds per kilometer, which is 3:45/km — or 6:02 per mile, at 16 km/h.
Is 1600 meters the same as a mile?
Almost. A mile is 1609.344 meters, so four laps of a 400 m track leaves you 9.344 meters short — about 2.1 seconds at 6-minute mile pace, which is 4.4704 m/s. That is why races are posted as either 1600 m or 'the mile', never both.
How many laps of a track is a mile?
4.02 laps of a standard 400-meter track. Older US tracks built to 440 yards measure 402.34 meters per lap, where four laps come to 1609.34 meters — a true mile, which is where the phrase 'four laps is a mile' came from.
How much faster than race pace should intervals be?
Fast enough that you could not hold it for the race distance — that is the entire point of breaking the effort into pieces. Compare the pace this page returns with your 5K or 10K target and the gap is your workout intensity.
How many repetitions should a track workout have?
There is no universal number. The usable signal is consistency: if the last repetition is markedly slower than the first, the session was too long or started too fast, and the extra repetitions taught you nothing.
Sources
- World Athletics — 400 Metres (one lap of a standard outdoor 400 m track; two laps of a 200 m indoor track)
- NIST Guide to the SI, Appendix B.9 — Factors for Units Listed Alphabetically (1 mile = 1.609 344 km; 1 yard = 0.9144 m exactly)
Written by Lucas Silva · Reviewed by Lucas Silva · Updated on August 15, 2026