Quick Answer
Swimming burns 400-700 calories per hour, depending on stroke and intensity.
For a 70kg (154lb) person, swimming burns: breaststroke 400-500 cal/hr, front crawl 500-700 cal/hr, backstroke 400-500 cal/hr, butterfly 600-800 cal/hr. Vigorous swimming can burn up to 900 calories per hour—comparable to running but joint-friendly.
Calorie Burn by Swimming Stroke
For 70kg (154lb) person, 1 hour of swimming:
| Stroke/Intensity | Calories Burned |
|---|---|
| Slow/Easy Swimming | 350-400 cal/hr |
| Breaststroke (Moderate) | 400-500 cal/hr |
| Backstroke | 400-500 cal/hr |
| Front Crawl (Moderate) | 500-700 cal/hr |
| Butterfly | 600-800 cal/hr |
| Vigorous Swimming (Intervals) | 700-900 cal/hr |
Factors Affecting Calorie Burn
Body Weight
Heavier people burn more calories. A 90kg person burns ~30% more than a 60kg person at the same intensity.
Intensity
Vigorous swimming burns 2x more calories than easy swimming. Interval training maximizes calorie burn.
Stroke Choice
Butterfly burns the most (full-body power), breaststroke the least (more glide time).
Swimming Efficiency
Beginners burn more calories due to poor technique. As you improve, you burn slightly fewer calories for the same distance.
Swimming vs Other Exercise
Calories burned per hour (70kg person):
- Swimming (vigorous): 700-900 calories
- Running (10 km/h): 700-800 calories
- Cycling (vigorous): 600-750 calories
- Walking (6 km/h): 300-350 calories
- Yoga: 200-300 calories
Swimming ranks among the highest calorie-burning exercises, with the added benefit of zero joint impact.
The Bottom Line
Swimming burns 400-700+ calories per hour, making it one of the most effective calorie-burning exercises. A 30-minute session burns 200-350 calories—excellent for weight loss and fitness.