A statute mile is 70.4 lengths of a 25-yard pool, 64.4 lengths of a 25-metre pool, or 32.2 lengths of a 50-metre pool. Almost everyone calls those "laps", so those are the numbers most people want. Counted strictly — a lap being a round trip, down and back — you would halve them, which is where the conflicting answers come from.
A Lap Is Not a Length
This is why most answers to "how many laps is a mile" are wrong, and why two people can both be right while giving numbers that differ by half.
Strictly, a length is one end of the pool to the other, and a lap is a round trip — down and back — exactly as on a running track. In practice, almost every swimmer, coach and poolside notice uses "lap" to mean one length.
So when someone says a mile is 70 laps in a 25-yard pool, they mean 70 lengths. Someone using the strict definition would say 35. Both figures appear online, usually without saying which is meant. The calculator above gives you both.
How Many Lengths in a Mile
| Pool | Lengths per mile | Laps (round trips) |
|---|---|---|
| 25 yards (US short course) | 70.4 | 35.2 |
| 25 metres (short course) | 64.4 | 32.2 |
| 50 metres (Olympic) | 32.2 | 16.1 |
| 20 metres | 80.5 | 40.2 |
| 33⅓ metres | 48.3 | 24.1 |
| 15 metres (hotel pool) | 107.3 | 53.6 |
Based on a statute mile of exactly 1609.344 metres (1760 yards). A 25-yard pool is 22.86 metres.
The Swimmer's Mile Is Not a Mile
Two conventions circulate in swimming, and neither is a true mile:
- 1650 yards — the short-course yards "mile", 66 lengths of a 25-yard pool. That is 1508.8 metres, about 100 metres short of a statute mile.
- 1500 metres — the metric mile and the Olympic distance, 60 lengths of a 25-metre pool or 30 of a 50-metre. Also about 109 metres short.
Both exist because they divide cleanly into pool lengths, and a true mile does not — it is 70.4 lengths of a 25-yard pool, which is an awkward number to count and an even more awkward one to race. If you specifically want to have swum a mile, swim 71 lengths in a 25-yard pool or 65 in a 25-metre one.
Why Pool Length Changes the Workout
A mile in a 20-metre pool is 80 turns. A mile in a 50-metre pool is 32. Turns are where much of the effort goes, and also where much of the recovery happens — you push off the wall with more speed than you were swimming with.
That is why the same distance feels different in different pools, and why times are not comparable between short course and long course. Short-course times are faster for the same swimmer, which is why records are kept separately for each.
Counting Without Losing Track
- Count in sets. Ten lengths at a time is far easier to hold than counting to seventy.
- Use the clock. Note your start time and your pace per 100; the distance follows without counting at all.
- Move something. A hair tie moved from one wrist to the other every ten lengths survives the point where concentration does not.
- Check the pool length first. Many gym and hotel pools are neither 25 yards nor 25 metres. The tool above takes any length — measure it once and the number is right thereafter.