Calories Burned Calculator
Estimate how many calories you burn during exercise, from walking to HIIT, based on your weight, the activity, and how long you do it.
How the calories burned calculator works
Calorie burn is estimated with METs, or metabolic equivalents. One MET is roughly the energy you use sitting still, so an activity rated at 8 METs burns about eight times as much. The formula multiplies the activity MET value by your weight and time.
The MET formula
Calories burned equals METs times your weight in kilograms times the duration in hours. Heavier bodies and longer or harder sessions burn more. The MET values here come from the Compendium of Physical Activities, the standard reference researchers use.
Why it is an estimate
MET values are population averages, so your real burn depends on intensity, fitness, technique, and body composition. Fitness trackers face the same limits. Use the number as a reasonable guide, and remember that diet drives weight change far more than exercise calories do.
Frequently asked questions
How are calories burned calculated?
This calculator uses the MET method: calories burned equals the activity MET value times your weight in kilograms times the time in hours. MET stands for metabolic equivalent, a standard measure of exercise intensity from the Compendium of Physical Activities.
How accurate is a calories burned calculator?
It is a good estimate, not an exact count. MET values are averages, so your real burn shifts with intensity, fitness, and body composition. Even chest-strap heart-rate monitors only estimate. Treat the result as a ballpark and focus on consistency over precision.
Does body weight affect calories burned?
Yes, a lot. The same activity for the same time burns more calories for a heavier person, because moving more mass takes more energy. That is why this calculator asks for your weight, and why generic calories-per-minute charts can be misleading.
Should I eat back the calories I burn from exercise?
Usually not all of them. Because exercise burn is often overestimated, eating it all back can stall weight loss. If you are in a deficit, a common approach is to base intake on your overall activity level and only add a portion back after long or intense sessions.
Does exercise or diet matter more for weight loss?
Diet usually matters more. It is far easier to eat 500 calories than to burn 500, so most sustainable weight loss comes from the calorie deficit on your plate. Exercise is excellent for health, muscle, and appetite, and it supports the deficit rather than replacing it.