Calorie Burn Calculator
Estimate calories burned during exercise from MET value, body weight, and duration. Use it to track exercise contribution to daily calorie balance and compare relative energy cost across different activities.
Last updated: May 2026
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About this calculator
The formula is: calories burned = MET × weight (kg) × (duration in minutes / 60). The MET (Metabolic Equivalent of Task) is a standardized unit where 1 MET = resting metabolic rate (~1 kcal/kg/hour). Multiplying by weight gives kcal/hour at that intensity; dividing duration by 60 converts to hours. MET values come from the Compendium of Physical Activities (Ainsworth et al., 2011 update). Common values: sitting 1.0; brisk walking 4-5; bicycling moderate 6-8; running 8-min/mile 12; running 6-min/mile 16; swimming moderate 7-8; weightlifting moderate 5-6; HIIT 8-12; rock climbing 8-11. The MET system standardizes intensity comparisons across activities. Public health guidelines (CDC, WHO) recommend 150 minutes of moderate activity (3-6 METs) per week, or 75 minutes vigorous (6+ METs), or equivalent combinations. Edge cases: zero weight, MET, or duration produces zero calories. The formula gives population averages; individual energy expenditure varies 10-30% from the calculated number based on fitness level (trained athletes burn fewer calories at the same external intensity due to better metabolic efficiency), body composition (more muscle = higher metabolism), age, sex, and movement efficiency. Heart-rate-based estimates from fitness trackers and smartwatches can be more accurate than MET-based formulas because they capture individual cardiovascular response, but even those have ~15-25% error vs. lab gold-standard indirect calorimetry. For weight management, treat any calorie-burn estimate as directional rather than precise.
How to use
Example 1 — Moderate exercise. 75 kg person bikes moderately (MET 7) for 45 minutes. Enter 75 for Weight, 7 for MET, 45 for Duration. Result: 75 × 7 × (45/60) = 75 × 7 × 0.75 = 393.75 calories. ✓ Reasonable estimate; real expenditure may range 350-450 calories depending on individual factors. For broader fitness purposes, accumulated minutes of moderate activity matter more than precise calorie burns per session. Example 2 — High-intensity workout. 60 kg person does HIIT (MET 10) for 25 minutes. Enter 60, 10, 25. Result: 60 × 10 × (25/60) = 60 × 10 × 0.417 = 250 calories. ✓ HIIT also produces EPOC (excess post-exercise oxygen consumption), or "afterburn," that can add 5-15% more calories burned in the 24 hours after; this calculator doesn't capture EPOC. Total day's elevated metabolism from this session might be ~275-290 calories vs. 250 measured.
Frequently asked questions
How accurate are MET-based calorie estimates?
Population averages with ±10-30% individual variation. The Compendium of Physical Activities (Ainsworth et al., 2011) is the standard MET reference, used by researchers and health organizations. Individual variation comes from: fitness level (trained athletes burn fewer calories at same external work due to better metabolic efficiency); body composition (more muscle = higher metabolism); age (decreases slightly); sex; movement efficiency. Heart rate-based estimates (Polar, Garmin, Apple Watch) attempt to personalize by capturing individual cardiovascular response, with ±15-25% error vs lab gold standard. The most accurate method is indirect calorimetry (measuring oxygen consumption in a lab), but it's impractical outside research settings. For weight management, treat all calorie-burn estimates as directional and adjust based on observed weight trends over weeks rather than relying on session-precision.
What's the difference between moderate and vigorous activity?
CDC categorization: light <3 METs (slow walking, light housework, sitting tasks); moderate 3-6 METs (brisk walking, casual cycling, dancing, gardening); vigorous 6+ METs (jogging, fast cycling, hiking, swimming laps, HIIT). The "talk test" provides a rough field test: moderate intensity allows talking but not singing; vigorous intensity makes talking difficult. Public health recommendations: 150 minutes of moderate weekly OR 75 minutes vigorous, OR equivalent combinations (each vigorous minute counts as 2 moderate minutes). Plus 2+ strength-training sessions per week. Moderate intensity has the most evidence for cardiovascular and metabolic benefits with lowest injury risk for most adults; vigorous intensity produces better fitness gains in less time but with higher injury risk and recovery cost. For long-term health and adherence, mostly moderate with occasional vigorous works for most adults.
Does this calculator include the "afterburn" effect?
No. EPOC (excess post-exercise oxygen consumption) — the elevated metabolism for hours after intense exercise — is not captured by simple MET-based formulas. EPOC is significant for high-intensity exercise: HIIT can add 5-15% more total calorie burn in the 24 hours after the workout, while moderate steady-state cardio adds 2-5%. Resistance training has notable EPOC effects too — heavy compound lifts (squats, deadlifts, presses) elevate metabolism for 24-48 hours via muscle protein synthesis. For practical weight management, EPOC is a small bonus that doesn't dramatically change total daily energy expenditure. Don't use EPOC as justification for caloric over-indulgence; the actual added calorie burn is modest. For comprehensive expenditure estimates, use a calorie-tracking app that includes EPOC adjustments for exercise type, or measure observed weight trends to empirically calibrate.
What are the most common mistakes calculating exercise calorie burn?
The biggest is over-estimating session calorie burn and "eating it back," leading to weight maintenance instead of loss; tracker errors plus self-reported intake errors compound. The second is fixating on session burn while ignoring NEAT (non-exercise activity thermogenesis) which can vary 200-800 calories/day between sedentary and active lifestyles. The third is using wrong MET values for an activity; the Compendium has dozens of intensity variants per activity (walking 2 mph vs 4 mph vs 5 mph, for example). The fourth is comparing calorie burn across activities at the same duration; 30 min running burns 2-3× more than 30 min yoga but they serve different fitness purposes. The fifth is treating fitness tracker numbers as precise when they have ±15-25% error. The sixth is forgetting that calorie burn depends on weight; as you lose weight, you burn fewer calories at the same activity. For weight management, weekly weigh-ins and 4-week trend analysis trump precise session-level calorie counting.
When should I not use this calculator?
Skip it for precise nutritional planning where you need accuracy under 5%; lab-grade indirect calorimetry is the only method that delivers that precision. It is the wrong tool for very high-intensity intervals where MET values are imprecise; heart-rate-based monitoring gives better individual estimates during HIIT. Do not use it for clinical purposes (post-surgery rehabilitation, cardiac event recovery) where exercise intensity needs precise medical supervision. For weightlifting and resistance training, MET values understate true energy expenditure because they don't capture EPOC; add 5-15% for resistance-heavy sessions. And for general weight management, treat calculator outputs as directional checks but not as precise budgets — combine with weekly weigh-ins and adjust intake based on observed weight trend rather than precise calorie math. For elite athletes, use sport-specific energy expenditure measurements (oxygen consumption testing) rather than MET-based estimates.