Low-intensity swimming burns 250 to 300 calories an hour, moderate-intensity swimming burns about 550 calories an hour, and high-intensity swimming burns 800 to 900 calories an hour. Low-intensity intermittent swimming may not even burn 200 calories an hour. In general, low-intensity swimming consumes 250 to 300 calories an hour, moderate-intensity swimming consumes about 550 calories an hour, and high-intensity swimming consumes 800 to 900 calories an hour. Low-intensity intermittent swimming may not even burn 200 calories an hour. But it should be noted that different people swimming an hour of calorie consumption is not the same, swimming calorie consumption and weight, swimming speed, swimming intensity, active heart rate, exercise time and so on. The same swim an hour, weight, swimming speed, swimming intensity, active heart rate of people consume more calories. Swimming is good for health, but swimming intensity and time should be flexible to avoid discomfort caused by high-intensity exercise.