Swimming Calorie Calculator — Calories Burned Swimming
See how many calories you burn in the pool: choose your stroke, enter your body weight and session length, and get gross caloric expenditure, net calories, and estimated fat burned — all based on published MET values.
Units
kg
min
Stroke / activity
Total energy including resting metabolic rate during swimming
- 1
Duration in hours
45 min ÷ 60 = 0.75 - 2
MET × body weight
8.3 × 70 kg = 581MET value from the Compendium of Physical Activities (Ainsworth et al., 2011). - 3
Gross calories burned
8.3 × 70 × 0.75 h = 436
How does this calculator work?
Swimming calories = MET × weight (kg) × time (hours). METs range from 3.5 (treading water) to 13.8 (butterfly). A 70 kg swimmer doing moderate freestyle for 45 minutes burns about 434 kcal gross and 374 kcal net. Butterfly burns ~50% more calories than freestyle at the same duration.
Formula
How this is calculated
Metabolic Equivalent of Task (MET) values express how much harder an activity is than sitting at rest (1 MET). Swimming METs range widely by stroke and effort: leisurely non-lap swimming is about 6.0 MET, moderate freestyle crawl is 8.3 MET, and butterfly — one of the most demanding strokes — reaches 13.8 MET. The values used here come from the 2011 update to the Compendium of Physical Activities (Ainsworth et al.), the most widely cited reference in exercise science. Gross caloric expenditure is MET × body weight in kg × duration in hours; this includes the resting metabolic rate that would have been burning anyway.
Net calories strip out that resting component by using (MET − 1) × weight × hours, giving a truer picture of the extra energy expended by swimming. Fat oxidation during moderate aerobic swimming contributes roughly 85% of net energy; dividing by 9 kcal/g of fat gives an approximate fat-burned figure. In practice the fat-to-carbohydrate ratio varies with swim intensity, individual fitness and how well-fed the swimmer is, so treat it as an estimate.
The calculator does not adjust for water temperature (cold water increases caloric burn via thermogenesis), swimming efficiency, altitude, or interval versus continuous swimming. High-level competitive swimmers are significantly more efficient than recreational swimmers at the same speed, so their effective MET at a given pace is lower.
Frequently asked questions
For a 70 kg person: moderate freestyle (MET 8.3) burns about 290 kcal gross; breaststroke general (MET 5.3) burns about 185 kcal; butterfly (MET 13.8) burns about 483 kcal. Lighter swimmers burn proportionally fewer calories because the MET formula scales with body mass.
Butterfly requires simultaneous arm pulls with a powerful undulating kick, engaging the core, chest, shoulders, back and legs at high intensity all at once. Its MET of 13.8 is higher than running at 16 km/h (MET ~14.5), making it one of the most calorically demanding exercises available. Most recreational swimmers cannot sustain it for long.
Per km, swimming generally burns more calories than running for most people because water's resistance is ~800× greater than air. However, competitive swimmers move more efficiently than recreational runners, narrowing the gap. Per minute, vigorous swimming (MET 9.8) is roughly comparable to running at 10 km/h (MET 9.8).
Also known as
TG we-Calculate Editorial Team. (2026). Swimming Calorie Calculator — Calories Burned Swimming [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/swimming-calorie-calculator
TG we-Calculate Editorial Team. "Swimming Calorie Calculator — Calories Burned Swimming." TG we-Calculate. 2026. https://we-calculate.com/calculator/swimming-calorie-calculator.
TG we-Calculate Editorial Team, "Swimming Calorie Calculator — Calories Burned Swimming," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/swimming-calorie-calculator
@misc{wecalculate_swimming_calorie_calculator, title = {Swimming Calorie Calculator — Calories Burned Swimming}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/swimming-calorie-calculator}}, year = {2026}, note = {TG we-Calculate} }
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