Calorie Burn Estimator
Estimate calories burned during any exercise using your weight, activity type, and duration.
How this is calculated
kcal burned = MET × body weight (kg) × duration (hours), using published MET values for each activity. The food and drink equivalents divide that figure by typical calorie counts for a Mars bar (230kcal), a slice of pizza (285kcal), and a pint of beer (215kcal).
This calculation covers only the calories burned during the activity itself — it doesn't include the "afterburn" effect (EPOC), where your body continues consuming extra oxygen and burning calories for hours after a workout ends while it restores itself to a resting state. High-intensity exercise like HIIT produces significantly more EPOC than steady-state cardio at the same overall calorie burn, which is one reason high-intensity training is often favoured for its total metabolic effect beyond the session itself. To put your activity level in the context of your body composition and daily calorie needs, see the BMI & Body Weight calculator, and for hydration needs during exercise, see the Daily Water Intake calculator.
Frequently asked questions
- What is a MET value?
- Metabolic Equivalent of Task — a measure of how many times more energy an activity burns compared to sitting quietly. A MET of 8 means you burn roughly 8x the calories you'd burn at rest, published from exercise science research.
- Why does body weight matter so much?
- Heavier bodies burn more calories doing the same activity, since more mass requires more energy to move. The formula scales directly with weight: kcal = MET × weight (kg) × duration (hours).
- How accurate is this?
- MET-based estimates are a widely used approximation, not a precise measurement — actual burn varies with fitness level, intensity, terrain, and individual metabolism. Wearable heart-rate-based estimates are generally more personalized, but MET tables are a solid ballpark.
- Can I use this in my own app?
- Yes — every calculator on Stupidly Clever has a matching REST API and MCP tool that runs the same underlying logic.
- How is calorie burn estimated?
- Calorie burn is estimated as MET × body weight (kg) × duration (hours). The MET value for your chosen activity comes from published exercise science tables, and multiplying by your weight and time gives an estimate of total calories burned during that session.
- Does fitness level affect calorie burn?
- Yes, though MET tables don't capture it directly — a fitter person typically works at a lower relative intensity (and burns somewhat fewer calories) doing the same activity at the same pace as a less-fit person, since their cardiovascular system is more efficient. MET-based estimates are a population average, not personalized to your specific fitness level.
- What is EPOC (the afterburn effect)?
- Excess Post-exercise Oxygen Consumption (EPOC), commonly called "afterburn," is the elevated calorie burn that continues after a workout ends while your body restores itself to a resting state. High-intensity exercise produces more EPOC than steady, low-intensity activity — see below for how this can meaningfully add to your total calorie burn beyond the session itself.