Swim Pace Calculator

Written byOleh Soloninupdated 25 September 2026

Distance, m

Minutes

Seconds

Pool length, m

Result

Pace per 100 m1:40 per 100 m
Pace per 50 m0:50 per 50 m
Time per length0:25 per length
Lengths60
Speed, m/s1
Speed, km/h3.6

This result is informational only and is not professional advice.

Swimmers count hundreds, not kilometres

Works out pace per hundred metres, speed and time per length from a distance and a total time.

Runners measure pace in minutes per kilometre; swimmers use minutes per hundred metres. Speeds in the water are low: a 1:40 pace per 100 m is exactly a metre a second, 3.6 km/h, and a per-kilometre pace would give awkwardly large numbers.

It also helps to know the time per length: that is what the pace clock shows, and the easiest way to hold your splits during a swim.

How to use

Enter the distance in metres.
Enter your time in minutes and seconds.
Enter the pool length: 25 or 50 metres.
The result gives pace per 100 and per 50 metres, speed, the number of lengths and the time per length.

Pace over 1,500 metres

Every five minutes over 1,500 metres moves the pace by 20 seconds per 100. A 30-minute 1,500 is 2:00 per 100 m and 30 seconds per 25-metre length.

Every row comes from the calculator on this page.
1500 m time	Per 100 m	Per 50 m	Per 25 m length	Speed, km/h
20:00	1:20	0:40	0:20	4.5
22:00	1:28	0:44	0:22	4.09
25:00	1:40	0:50	0:25	3.6
30:00	2:00	1:00	0:30	3
35:00	2:20	1:10	0:35	2.57
40:00	2:40	1:20	0:40	2.25

25 and 50 metre pools

Pool length does not change the pace per 100 m, but it changes the splits: 1,500 metres is 60 lengths of 25 m or 30 of 50. At 1:40 per 100, one 50-metre length takes 50 seconds.

1500 m in 25:00. Every row comes from the calculator on this page.
Pool	Lengths in 1500 m	Time per length at 1:40 per 100 m
25 m	60	0:25
50 m	30	0:50

What this calculator shows

Pace per hundred and per fifty metres
Speed in metres a second and kilometres an hour
The number of lengths and the time for one

What to keep in mind

The figure is an average across the whole distance; a real swim is almost never evenly paced.
Pool length changes the number of lengths and the split per length, but not the pace per hundred.

FAQs

How do I work out swim pace per 100 m?

Divide the time in seconds by the distance and multiply by a hundred. 1,500 metres in 25 minutes is 1,500 seconds over 1,500 metres — 100 seconds, or 1:40, per 100.

How many lengths are in a kilometre?

Forty in a 25-metre pool and twenty in a 50-metre one. 1,500 metres is sixty and thirty respectively.

What pace swims 1,500 m in 30 minutes?

2:00 per 100 m, or 30 seconds per 25-metre length. For 25 minutes, 1:40; for 20 minutes, 1:20.

Why are times faster in a 25 m pool?

Because of the turns: pushing off the wall and gliding underwater is faster than swimming. A long-course pool has half as many.

How do I convert swim pace to speed?

Divide a hundred by the time in seconds to get metres per second. A 1:40 pace per 100 is exactly 1 m/s, or 3.6 km/h.

How do I hold an even pace during a swim?

By the time per length: aiming for 1:40 per 100, each 25-metre length should take 25 seconds. The pace clock or your watch shows it after every turn.

Worked example

1,500 metres in twenty-five minutes

Input: 1500 m in 25:00 in a 25 m pool

Output: 1:40 per 100 m, 60 lengths at 0:25 each

Note: Exactly one metre a second is a handy reference point. The 1500 m freestyle world record is under 14 minutes 32 seconds — faster than 0:59 per 100 m.

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Result

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