Activity calories · 2024 Compendium METs

Calories burned swimming

Quick answer

A 70 kg (154 lb) person burns about 203 kcal in 30 minutes of swimming (Freestyle laps, slow, recreational), and about 406 kcal in an hour. That is 5.8 METs.

30 minutes: 203kcal; 70 kg (154 lb)
1 hour: 406kcal; 70 kg (154 lb)
1 hour: 348kcal; 60 kg (132 lb)
1 hour: 464kcal; 80 kg (176 lb)

Swimming is rated by stroke and effort, and the spread is wide: a relaxed backstroke is a moderate effort, fast butterfly one of the highest ratings in the Compendium. Lap swimming at a slow recreational pace is the usual starting point; leisurely swimming that is not lap swimming is listed separately.

Calculate calories burned swimming

Starts at 70 kg (154 lb) for 30 minutes of swimming at 5.8 METs; enter your own weight and time.

Calories burned swimming by weight and time

Kilocalories for swimming at 5.8 METs (Freestyle laps, slow, recreational), by body weight and minutes. Read across from your weight; the pace table below shows the other rows.

Calories burned swimming at 5.8 METs, by body weight and duration
Body weight	15 min	30 min	45 min	1 hour	1.5 hours	2 hours
50 kg (110 lb)	73	145	218	290	435	580
60 kg (132 lb)	87	174	261	348	522	696
70 kg (154 lb)	102	203	305	406	609	812
80 kg (176 lb)	116	232	348	464	696	928
90 kg (198 lb)	131	261	392	522	783	1,044
100 kg (220 lb)	145	290	435	580	870	1,160
110 kg (243 lb)	160	319	479	638	957	1,276

Swimming: calories by pace or effort

The Compendium rates swimming on 9 lines, from 4.8 METs (Backstroke, recreational) up to 13.8 METs (Butterfly). Each row below is one of those codes with the calories it works out to.

Calories burned swimming by pace or effort
Pace or effort	Compendium code	METs	30 min, 60 kg (132 lb)	30 min, 70 kg (154 lb)	30 min, 80 kg (176 lb)	1 hour, 70 kg (154 lb)
Backstroke, recreational	18255	4.8	144	168	192	336
Breaststroke, recreational	18265	5.3	159	186	212	371
Freestyle laps, slow, recreational	18240	5.8	174	203	232	406
Leisurely, not lap swimming	18310	6	180	210	240	420
Crawl, medium speed (about 50 yd/min)	18290	8	240	280	320	560
Freestyle laps, fast, vigorous	18230	9.8	294	343	392	686
Breaststroke, training or competition	18260	10.3	309	361	412	721
Crawl, fast (about 75 yd/min)	18280	10.5	315	368	420	735
Butterfly	18270	13.8	414	483	552	966

The Compendium’s own wording for each code: 18255, “Swimming, backstroke, recreational”; 18265, “Swimming breaststroke, recreational”; 18240, “Swimming laps, freestyle, slow, recreational”; 18310, “Swimming, leisurely, not lap swimming, general”; 18290, “Swimming, crawl, medium speed, ~50 yards/minute, vigorous effort”; 18230, “Swimming laps, freestyle, fast, vigorous effort”; 18260, “Swimming, breaststroke, general, training or competition”; 18280, “Swimming, crawl, fast speed, ~75 yards/minute, vigorous effort”; 18270, “Swimming, butterfly, general”.

What changes the number for swimming

Pace is the biggest lever. The hardest listed way of swimming (Butterfly) is rated at 13.8 METs, 2.9 times the 4.8 METs of the gentlest (Backstroke, recreational). For a 70 kg (154 lb) person that is 966 kcal an hour against 336 kcal.

Body weight is the second: the same 5.8 METs of swimming for 30 minutes comes to 145 kcal at 50 kg (110 lb) and 319 kcal at 110 kg (243 lb). To reach 100 kcal at 70 kg (154 lb) takes about 15 minutes at the starting pace.

Laid out in half-hour terms for 70 kg (154 lb): backstroke, recreational is 168 kcal; breaststroke, recreational is 186 kcal; freestyle laps, slow, recreational is 203 kcal; leisurely, not lap swimming is 210 kcal; crawl, medium speed (about 50 yd/min) is 280 kcal; freestyle laps, fast, vigorous is 343 kcal; breaststroke, training or competition is 361 kcal; crawl, fast (about 75 yd/min) is 368 kcal; butterfly is 483 kcal.

How the calories are worked out

The formula is calories = MET × body weight in kg × hours. A MET compares an activity with sitting quietly, which is 1 MET and is taken as roughly 1 kcal per kilogram per hour. That equivalence is an approximation, which is why every figure is rounded and called about.

For swimming at 5.8 METs, a 70 kg (154 lb) person for 30 minutes: 5.8 × 70 × 0.5 = 203 kcal. This is a gross figure: it includes the energy your body would spend at rest in the same time.

The MET values are those of the 2024 Adult Compendium of Physical Activities (Herrmann SD, Willis EA, Ainsworth BE, et al., J Sport Health Sci 2024), read from its activity list on 2026-10-23 and copied with their codes. They are averages for adults; see how we calculate.

Frequently asked questions

How many calories does a 70 kg person burn swimming in 30 minutes?

About 203 kcal at 5.8 METs (Freestyle laps, slow, recreational). The whole range for swimming on this page runs from 168 kcal (Backstroke, recreational) to 483 kcal (Butterfly) in the same half hour.

How many calories does swimming burn in an hour?

At 5.8 METs, about 348 kcal for a 60 kg (132 lb) person, 406 kcal at 70 kg (154 lb) and 464 kcal at 80 kg (176 lb). Heavier people burn more because they move more mass.

How long does swimming take to burn 100 calories?

For a 70 kg (154 lb) person, about 15 minutes at 5.8 METs (Freestyle laps, slow, recreational). At the gentlest listed pace (Backstroke, recreational, 4.8 METs) it takes 18 minutes, and at the hardest (Butterfly, 13.8 METs) about 6.

Does the number for swimming include the calories I would burn anyway?

Yes. Of the 5.8 METs, 1 is the resting cost, about 17% of the total here, so the activity itself adds about 168 of the 203 kcal in 30 minutes at 70 kg (154 lb).

Why would my watch show a different number for swimming?

A watch uses its own model, often with heart rate, age and sex, while this page uses the Compendium’s average. For swimming that average already spans 9 entries from 4.8 to 13.8 METs, a 2.9-fold range, so a gap between the two is normal.

Which line in the table should I choose for swimming?

Pick the row that best describes how you did it: this page starts from “Freestyle laps, slow, recreational”, about 11% of the way up the 4.8 to 13.8 MET range. The rows are separate Compendium entries (18255, 18265, 18240, 18310, 18290, 18230, 18260, 18280, 18270).

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These are estimates for healthy adults from average MET values. How much you actually burn varies with your fitness, body composition, technique, terrain and conditions, so use the figures as a guide, not a measurement. This is not medical advice.