Calories for swimming?

How many calories burnt swimming 1km in 40 minutes? I weight 67kg.?

• Hi there, Roughly how many calories do I burn swimming 1km/40 lengths (25m). I weight 76kg and Male. Just started, it was like my first swim in about 3 months. I pushed myself medium - could have gone harder but also could have relaxed more. If there is a way to measure how many calories are burnt pre length (25m), knowing my weight sex etc, please let me know where/how. Many Thanks

• Answer:

  Its roughly 1000 calories an hour providing your bmi is in the "normal weight" zone, and that you pushing yourself to almost max speed, say 80% of you fastest length. Considering you went "medium" id say you probably burnt between 300-500. Its not the length, its the speed.