Calories Burned Calculator (MET-based) — Free | RECATOOLS — Practical Tools. Trusted Intelligence.

How to use the calories burned calculator

Pick your activity

Choose from 35+ activities. MET values come from the 2011 Compendium of Physical Activities (Ainsworth) — the global standard reference used in research and clinical practice. Each activity's MET value reflects the average energy cost relative to resting (MET 1 = baseline resting metabolism).

Enter weight + duration

Weight in kg (lbs ÷ 2.2046). Duration in minutes — actual moving time, not total session time including breaks. The MET formula: kcal = MET × weight × hours. Linear in both inputs — double weight = double calories; double duration = double calories.

Read calories burned

The headline number is total kcal burned during the activity. Caveats: MET-based estimates are AVERAGES across population. Individual variation can be ±15-25% due to fitness level, age, sex, body composition. Treadmill calorie displays use similar MET-based math; fitness trackers add HR-based adjustments.

Cross-check with fitness tracker

Garmin, Apple Watch, Polar, Whoop use HR-based + accelerometer-based estimation that's generally 5-15% more accurate than pure MET for individual users (because they account for your fitness via HR response). MET-based is the population-level estimate; HR-based is personalised.

Apply for weight management

7,700 kcal ≈ 1 kg fat mass equivalent. A 30-min moderate run burns ~300 kcal = ~40 g of fat-equivalent. Sustainable fat loss comes from CHRONIC modest deficit (300-500 kcal/day), not heroic exercise sessions. Exercise primarily for fitness; diet primarily for weight management.

MET — the scientific way to estimate exercise calories

The Metabolic Equivalent of Task (MET) system, formalised in the Compendium of Physical Activities (Ainsworth et al, 2011), assigns each activity a multiplier of resting metabolism. 1 MET = the energy cost at quiet rest (~3.5 mL O2/kg/min, or ~1 kcal/kg/hour). Walking briskly = 5 METs = 5× resting metabolism. Running fast = 11-14 METs. The MET system standardises exercise energy expenditure across activities, populations, and research studies. Clinical practice, public health guidelines (WHO 150 min/week of moderate activity = 4-6 METs), and research all use METs. Population-level accuracy is good; individual-level accuracy is ±20% due to fitness, body composition, training status.

kcal = MET × weight (kg) × hours

The math is simple. A 70 kg adult running at 10 km/h (MET 10) for 30 minutes: 10 × 70 × 0.5 = 350 kcal. Same person walking at 5 km/h (MET 3.5) for 30 min: 3.5 × 70 × 0.5 = 122.5 kcal. The linear formula means: heavier individuals burn more calories at the same exercise; longer sessions scale linearly; harder exercise (higher MET) scales linearly. This is approximate — actual energy cost varies with terrain, fitness, technique, heat — but population-level estimates are robust.

"You can\'t outrun a bad diet" — 30 minutes of moderate running burns ~300 kcal. A donut is ~250 kcal. Exercise is for fitness; diet is for body composition. The math is brutal but useful.

Why fitness trackers disagree with MET estimates

Modern wearables (Apple Watch, Garmin, Whoop, Polar) use HR-based + accelerometer-based proprietary algorithms calibrated to individual users over time. They typically read 10-20% different from MET-based estimates for the same activity. Neither is definitively correct — trackers personalise to your HR response (better for individuals); MET is the standardised research framework. For meaningful comparisons over time, pick one method and stick with it. Switching between MET-based and tracker-based estimates compromises trend tracking.

ASEAN exercise context

Heat-stressed exercise (typical ASEAN climates): cardiovascular drift + thermoregulation costs ~10-20% additional calories at the same pace. A 30-min run that burns 300 kcal in temperate climate burns ~330-360 kcal in 32°C/85% humidity (Singapore, KL, Jakarta). Some calorie calculators don\'t adjust for heat; trackers using HR data partially capture it. For accurate ASEAN context, expect 10-20% higher real calorie burn at the same pace vs equation prediction in temperate environments.

10 Things to Know About MET

01

1 MET = quiet rest metabolism ≈ 3.5 mL O₂/kg/min ≈ 1 kcal/kg/hour.

02

kcal = MET × weight × hours. Heavier + longer + harder = more calories.

03

Compendium of Physical Activities (Ainsworth 2011) is the canonical MET reference.

04

WHO guideline: 150 min/week moderate activity (3-6 METs) for health.

05

Individual MET-vs-actual variation: ±15-25%. Tracker data is more personalised.

06

7,700 kcal ≈ 1 kg fat mass. The "calories in vs out" framework.

07

Heat adds 10-20% to caloric cost at same pace. ASEAN trainers note this matters.

08

Strength training MET 5-6 underestimates true cost — afterburn (EPOC) adds 5-15%.

09

Sleep is ~0.9 MET. Sitting at desk: ~1.5 MET. Office work isn\'t "rest" but barely above baseline.

10

"You can\'t outrun a bad diet": exercise for fitness, diet for body composition.

Frequently asked questions

Apple Watch (and other wearables) use HR-based algorithms calibrated to your individual HR response. MET-based estimates are population-level averages. Wearable values are typically 10-20% different (sometimes higher, sometimes lower). Neither is "wrong" — they\'re different methodologies. For trend tracking, pick one and stick with it.
The MET formula scales linearly with weight, so a 100 kg person burns ~40% more at the same activity than a 70 kg person. Individual variation around the MET prediction: trained athletes are slightly more efficient (lower true MET); untrained individuals are slightly less efficient (higher true MET). For most general use, MET values are accurate enough.
Yes — MET 5-6 typical for general strength training, 6+ for heavy compound lifts. But strength training has additional value: EPOC (excess post-exercise oxygen consumption) adds ~5-15% over the next 24-48 hours, and the muscle built raises long-term RMR. So "calories during the workout" underestimates total benefit.
Theoretically yes, practically no for most people. 30 min running burns ~300 kcal. A typical fast-food meal is 800-1,500 kcal. You\'d need to run 90+ minutes daily to offset poor diet. Diet has 10× the lever on body composition vs exercise. Exercise for fitness, cardiovascular health, longevity, mental health — diet for body composition.
Yes, 10-20% additional caloric cost in hot environments at the same pace, due to thermoregulation cost (cooling via sweat + skin blood flow). ASEAN-based runners burn more calories per session than identical workouts in temperate climates. Hydration cost is also higher. Heart rate runs higher at same pace.
Population-level accuracy is good (±10-15% on average across many subjects). Individual accuracy varies more: ±15-25% due to fitness, body composition, technique, environment. For weight-management decisions, treat MET-based estimates as approximations. Track over weeks/months for trends.
HIIT MET 8 is the work-interval average. Total session calories depend on work:rest ratio + duration. EPOC adds 5-15% over 24-48 hours, more than steady-state cardio. The "afterburn" makes HIIT efficient for caloric demand per minute, though steady-state Zone 2 is better for aerobic base building.
No. All inputs stay in your browser.
The full Compendium has 800+ activities. For activities not listed, find the closest match. Or look up the exact MET on the Compendium of Physical Activities website (sites.google.com/site/compendiumofphysicalactivities/).
Ainsworth BE. Med Sci Sports Exerc 2011;43:1575. WHO Physical Activity Guidelines. ACSM Guidelines for Exercise Testing + Prescription.

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Calories Burned Calculator