Calorie Burn by Activity Calculator
Estimate calories burned during exercise or daily activities using MET values and your body weight.
Exercise calorie estimates from cardio machines are notoriously inflated, often by 20–40%. MET-based calculations from body weight and activity type are more accurate for planning. I use these numbers to calibrate my TDEE estimate rather than relying on what the treadmill claims.
Calorie burn estimates are always approximations. Individual variation in metabolism, fitness level, terrain, and exact pace produce real differences. Use these as planning estimates, not precise measurements.
How MET-based calorie calculations work
MET (Metabolic Equivalent of Task) is a measure of exercise intensity relative to resting metabolism. A MET of 1.0 is resting. A MET of 8.0 means you're burning 8 times your resting metabolic rate. The formula: Calories per minute = MET × body weight in kg × 0.0175. Multiplied by duration gives total calories burned. This method is used by exercise physiologists and forms the basis of most calorie burn databases.
Why estimates vary between sources
Different sources use different MET values for the same activity (because MET varies with speed, intensity, and individual fitness), different formulas (some include resting calories, some calculate net calories above rest), and different base metabolic rates. The variation between sources is typically 10–20% for the same activity. The most authoritative MET database is the Compendium of Physical Activities maintained by Arizona State University.
Net vs gross calorie burn
This calculator estimates gross calories, total energy expenditure during the activity. Net calories would subtract what you'd burn at rest during the same time (approximately 1 kcal/kg/hour for most adults). For a 175-lb person sitting for 45 minutes, that's about 60 calories. Net calorie burn from a 45-minute run is gross calories minus 60. For planning energy balance, most people use gross calories from exercise, it's the convention most apps and diet trackers use.
Exercise and appetite
One important limitation of exercise as a weight loss tool: exercise increases appetite in many people, partially or fully compensating for calories burned. The research on exercise-induced weight loss alone (without dietary change) shows modest results for this reason. Exercise is extremely valuable for health, fitness, and body composition, but the calorie math often doesn't work out as cleanly as the burn number suggests.
Frequently asked questions
How accurate are fitness tracker calorie estimates?
Consumer fitness trackers overestimate calorie burn by an average of 27% according to a 2017 Stanford study across seven popular devices. They're useful for relative comparisons (comparing one workout to another) but not for precise calorie accounting. For dieters using exercise burn to justify eating more, this overestimation is consequential.
Does weight training burn many calories?
During the session, moderate weight training burns roughly 3.5–6 METs, less than running. But weight training's afterburn effect (EPOC, excess post-exercise oxygen consumption) extends calorie burn for 12–48 hours after heavy lifting sessions. This "afterburn" contributes meaningfully to total weekly energy expenditure even if the per-session calorie number looks modest.
What activity burns the most calories per hour?
Among common activities, vigorous cycling, running at fast paces, and competitive racket sports top the list at 700–1,000+ calories per hour for a 175-lb person. The actual number depends entirely on intensity, a slow jog burns far less than the same time at race pace.