Is the calculator accurate?
The calculator uses your basal metabolic rate (how much energy your body burns at rest) and the MET value (see below) for an activity to calculate calories burned. It does not take into account environmental factors, such as running into the wind or up hills, or a person's body composition, i.e. the amount of muscle versus fat (muscle burns more calories than fat).
What about exercise intensity?
The intensity at which you perform the activity will also affect how many calories you burn, however, this is factored in only for activities such as cycling or running where the pace can be easily measured.
How many calories to lose a kg of weight?
To lose 1 kg of weight, you need an energy deficit of 7500 kcals - assuming that your weight is stable and not increasing. That's equivalent to 31,380 kJ.
The deficit can come from reduced food intake, increased activity or both.
1 kilocalorie (kcal) = 1 Calorie = 4.184 kilojoules (kJ)
A MET is a concept used to compare the energy cost of different physical activities. One MET is equivalent to a metabolic rate consuming 1 kilocalorie per kg of bodyweight per hour, and is equivalent to your resting metabolic rate that is the energy your body uses to stay functioning at rest. An activity of 8 METs, such as singles tennis, would use 8 times as much energy as you do at rest.
Last Reviewed: 17 July 2015
- Ainsworth BE, Haskell WL, Whitt MC et al. Compendium of physical activities: an update of activity codes and MET intensities. Med Sci Sports Exerc 2000; 32(9): S498-S516 (suppl)