Exercise Calorie Burn Calculator
Estimates calories burned during exercise from your body weight, activity type, session duration, and intensity level. Use it to log workout energy expenditure or plan calorie targets around a training day.
About this calculator
This calculator estimates caloric expenditure using a MET-based (Metabolic Equivalent of Task) approach. METs quantify how many times more energy an activity demands compared to sitting at rest (1 MET ≈ 1 kcal/kg/hour). The formula is: Calories burned = MET × body weight (kg) × duration (hours) × intensity multiplier. In this calculator that is expressed as: Calories = activity_MET × weight × (duration / 60) × intensity_factor, where duration is in minutes and is divided by 60 to convert to hours. A higher MET value (e.g., running = ~9–11) burns far more calories than a low-MET activity (e.g., walking = ~3–4). Intensity modifiers scale the base MET up or down to reflect light, moderate, or vigorous effort within the same activity category.
How to use
Example: A 75 kg person cycles at a moderate intensity (MET ≈ 8) for 45 minutes with an intensity multiplier of 1.0. Calories = 8 × 75 × (45 / 60) × 1.0 = 8 × 75 × 0.75 = 450 kcal. At vigorous intensity (multiplier = 1.2): 8 × 75 × 0.75 × 1.2 = 540 kcal. That 90-calorie difference illustrates why intensity matters as much as duration. Enter your weight, choose your activity and intensity, and set the duration to see your estimated burn.
Frequently asked questions
How accurate are calorie burn calculators compared to heart rate monitors or lab testing?
MET-based calculators have an average error of 15–25% compared to indirect calorimetry (the lab gold standard), similar to the accuracy of most consumer heart rate monitors and fitness trackers. Individual factors like fitness level, heat, altitude, and muscle efficiency all affect true calorie burn but are not captured in a simple formula. Despite this margin, the calculator is useful for making relative comparisons — e.g., understanding that an hour of running burns roughly twice as many calories as an hour of walking at the same body weight. For precise dietary planning, treat the result as a useful estimate rather than an exact figure.
Does body weight significantly affect how many calories you burn during exercise?
Yes — heavier individuals burn more calories performing the same activity for the same duration because more mass requires more energy to move. A 90 kg person burns approximately 25% more calories than a 72 kg person doing the same workout. This is why the MET formula scales linearly with body weight. It also means that as you lose weight, your calorie burn per session gradually decreases at the same effort level, which is one reason why weight loss tends to plateau over time without adjusting duration or intensity.
What exercises burn the most calories per hour?
High-intensity activities with large muscle group involvement burn the most calories. Running at 10 km/h, cycling vigorously, rowing, and jump rope all carry METs between 9 and 12, burning 600–900+ kcal/hour for a 75 kg person. HIIT (high-intensity interval training) can temporarily exceed these values and also creates an 'afterburn' effect (excess post-exercise oxygen consumption, or EPOC) that extends calorie burning for hours after the session ends. Lower-impact activities like walking (MET ≈ 3–4) or gentle yoga (MET ≈ 2–3) burn significantly fewer calories per hour but are sustainable for longer durations.