Swimming Calorie Calculator
Swimming is one of the highest-burn everyday workouts because water resists every movement. Pick your stroke and effort, enter weight and time in the pool, and get a research-based calorie estimate.
Example: with Your weight (lb) 170 · Stroke and effort Freestyle laps - light/moderate (5.8 METs) · Time in the water (minutes) 30 → Calories burned: 224 kcal.
Computed by the calculator below using its default values. Change any input to see your own numbers.
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Check it outHow many calories do you burn swimming?
The formula is calories = MET × weight (kg) × hours, with the MET set by stroke and effort. A 170 lb (77.1 kg) swimmer doing moderate freestyle laps (5.8 METs) for 30 minutes burns 5.8 × 77.1 × 0.5 ≈ 224 kcal — about 447 kcal per hour. Push to a fast, vigorous freestyle (9.8 METs) and the same half hour jumps to about 378 kcal, roughly 756 kcal per hour.
Per hour at 170 lb: recreational backstroke ≈ 370 kcal, breaststroke ≈ 409 kcal, leisurely (non-lap) swimming ≈ 463 kcal, moderate treading ≈ 270 kcal. For comparison, a 3.0 mph walk manages only about 270 kcal per hour — the pool delivers a running-level burn with none of the joint impact. Lighter swimmers burn proportionally less: about 171 kcal per 30-minute moderate session at 130 lb.
How it’s calculated
Calories = MET × body weight (kg) × duration (hours). MET values come from the 2011 Compendium of Physical Activities: freestyle laps light/moderate 5.8, freestyle fast/vigorous 9.8, breaststroke recreational 5.3, backstroke recreational 4.8, leisurely non-lap swimming 6.0, treading water moderate 3.5. Pounds convert at 1 lb = 0.45359237 kg. Totals are gross (they include resting metabolism).
Results update as you type and are estimates, not professional advice — verify important decisions with a qualified professional.
Common mistakes
- Copying pool-timer minutes into the formula — MET values assume time actually swimming, so subtract wall rest between laps.
- Using one number for all strokes — vigorous freestyle (9.8 METs) burns roughly double recreational backstroke (4.8).
- Rewarding the swim with a full meal — a 224 kcal half hour is undone by one 500 kcal snack.
Frequently asked questions
How many calories does 30 minutes of swimming burn?
About 224 kcal for a 170 lb swimmer doing moderate freestyle laps, or 378 kcal at a vigorous pace. A 130 lb swimmer burns about 171 kcal at moderate effort.
How many calories does swimming burn per hour?
At 170 lb: roughly 447 kcal for moderate freestyle laps, 756 kcal for fast freestyle, 409 kcal for breaststroke, 370 kcal for backstroke, and 463 kcal for casual non-lap swimming.
Does swimming burn more calories than walking?
Yes, per hour of actual activity. Moderate laps (5.8 METs) burn about 447 kcal per hour at 170 lb, versus about 270 kcal for a 3.0 mph walk (3.5 METs).
What burns the most calories in the pool?
Of the everyday options, fast vigorous freestyle at 9.8 METs (about 756 kcal per hour at 170 lb). Butterfly rates even higher in the Compendium but few swimmers can hold it for long.