Swimming Calorie Calculator

Swimming burns 300-900+ calories per hour depending on stroke and intensity. A 150 lb person burns approximately: 348 calories/hour freestyle slow, 498 calories/hour freestyle moderate, 600 calories/hour freestyle fast, 420 calories/hour backstroke, 618 calories/hour breaststroke, and 828 calories/hour butterfly. Butterfly is the most calorie-intensive stroke, burning nearly 2.4x more than slow freestyle. Heavier swimmers burn more calories - a 200 lb person burns 25-30% more than a 150 lb person at the same intensity.

Swimming and running burn similar calories, but each has advantages. Running burns slightly more per hour (600-900 cal/hr running vs 500-800 cal/hr swimming at comparable intensities), but swimming is zero-impact, works more muscle groups (full body vs lower body), and can be sustained longer without joint stress. Swimming is superior for: people with injuries, older adults, those over 200+ lbs, and building upper body strength. Running is better for: higher peak calorie burn, bone density, and convenience. For weight loss, choose the activity you will do consistently.

Butterfly burns the most calories at 13.8 METs (828 calories/hour for a 150 lb person), followed by breaststroke at 10.3 METs (618 cal/hr), freestyle fast at 10.0 METs (600 cal/hr), backstroke at 7.0 METs (420 cal/hr), and freestyle slow at 5.8 METs (348 cal/hr). Butterfly engages chest, shoulders, core, and legs simultaneously with explosive power. However, most swimmers cannot maintain butterfly for long periods. For sustained calorie burn, vigorous freestyle or breaststroke for 30-60 minutes is most effective, burning 300-600 calories per session.

Yes, swimming in cold water (below 70degF) burns 10-30% more calories than pool swimming due to thermogenesis - your body burning calories to maintain core temperature. Ocean swimming burns even more (20% extra) due to waves, currents, and salt water density. A 160 lb person swimming moderate freestyle burns 498 calories/hour in a warm pool, but 598-648 calories/hour in cold ocean water. However, very cold water (below 60degF) is dangerous without proper training. Most calorie burn comes from swimming intensity, not water temperature, so focus on stroke effort for best results.