Exercise Calories how do you calculate them?

lucan07

I notice lots of posts with exercise calories that are obviously high I know most machines over estimate, but is there actually a way of accurately calculating these calories using Heart Rate for example I use

http://www.shapesense.com/fitness-exercise/calculators/heart-rate-based-calorie-burn-calculator.aspx

and then calculate again on same site to get net results but still think results are high?

nytrifisoul

I have been told by a few personal trainers and doctors that HR is the most accurate way to calculate calorie burn.