Calories Burned Calculator

How we calculate calories burned

This calculator uses MET (Metabolic Equivalent of Task) values sourced from the Compendium of Physical Activities, a peer-reviewed research database developed by Arizona State University and used widely in exercise science and public health research. The formula is: Calories burned = MET x body weight (kg) x duration (hours). One MET represents the energy your body expends at complete rest — approximately 1 kcal per kilogram of body weight per hour, or roughly 3.5 ml of oxygen per kilogram per minute. An activity assigned a MET value of 8, such as running at 8 km/h, burns about eight times more energy than sitting still. The MET values used here represent averages across study populations and standardized conditions. Your actual calorie burn may differ based on several factors: cardiovascular fitness level (fitter individuals tend to burn fewer calories at the same intensity), exercise technique, environmental conditions such as temperature and altitude, and whether the activity is performed continuously or with rest intervals. For this reason, the result should be treated as a well-informed estimate rather than a precise measurement.

What your result means

Your estimated calorie burn is based on standardized MET values that represent average energy expenditure across study populations. In practice, your actual burn rate is influenced by numerous individual factors. Cardiovascular fitness plays a significant role — a highly trained runner burns fewer calories per kilometer than a beginner at the same pace because their body has become more efficient. Body composition matters too: muscle tissue is more metabolically active than fat tissue, so two people at the same weight may burn different amounts during identical activities. Environmental conditions such as heat, cold, humidity, and altitude also affect energy expenditure, as your body works harder to regulate temperature in extreme conditions. According to research published in the Journal of Sports Sciences, MET-based estimates are generally accurate within 15 to 20 percent for most individuals. Use this result as a practical guide for planning your nutrition and training balance. If you need greater precision, a chest-strap heart rate monitor or the Kalori app can help you refine your estimates over time.

Frequently Asked Questions