Calories Burned Calculator
How many calories did that workout burn? Three inputs, an answer in three seconds.
This value may be unrealistic — double-check your duration and weight.
Estimated calories burned
≈ kcal
That's roughly the same as…
Same time, other workouts
Estimates use the MET formula (2011 Compendium of Physical Activities). Actual burn varies with fitness, terrain and effort.
Understanding the MET method behind this calculator
Every "calories burned" number for an activity you didn't personally test in a lab is an estimate, and this calculator is no exception. What makes it useful rather than a guess is that it's built on the Metabolic Equivalent of Task (MET) system — a standardized scale researchers have measured across thousands of people doing hundreds of activities, published as the Compendium of Physical Activities. Instead of inventing a number for "jogging," this tool looks up the measured average intensity for that activity and scales it to your body weight and the time you spent doing it. That's the right tool when you want a quick, consistent way to compare a 30-minute swim against a 30-minute bike ride, or to sanity-check whether a workout "was worth it" relative to a snack.
Reading the inputs correctly
- Activity — pick the entry that matches your actual effort, not just the sport's name. "Running" is listed at several paces because a slow jog and a 10 km/h tempo run burn very differently; the closer your selection matches your real pace, the closer the estimate.
- Duration — enter only the active minutes. If you took a 5-minute break in the middle of a 45-minute session, the honest input is 40 minutes; padding in rest time inflates the result.
- Body weight — heavier bodies spend more energy moving the same distance, so this figure changes the output directly and proportionally. Switch the kg/lb toggle to match how you know your weight; the tool converts internally either way.
The formula behind the number
kcal burned = MET × 3.5 × weight (kg) ÷ 200 × duration (minutes)
Where does 3.5 and 200 come from? One MET is defined as roughly 3.5 ml of oxygen consumed per kilogram of body weight per minute — that's your body's oxygen use at rest. Multiplying by weight converts that to total oxygen volume, and dividing by 1000 then multiplying by about 5 kcal per liter of oxygen (the average energy released when the body burns a mixed diet) collapses into the single ÷200 constant. The formula is really just "oxygen used → energy released," scaled by how much harder than resting you're working (the MET value) and for how long.
Worked examples
Example 1 — Running at 8 km/h, 70 kg, 30 minutes
MET for this pace ≈ 8.3. Calculation: 8.3 × 3.5 = 29.05; 29.05 × 70 = 2,033.5; ÷ 200 = 10.17 kcal per minute; × 30 minutes ≈ 305 kcal.
Example 2 — Brisk walking, 60 kg, 45 minutes
MET for a brisk walk ≈ 3.5. Calculation: 3.5 × 3.5 = 12.25; 12.25 × 60 = 735; ÷ 200 = 3.68 kcal per minute; × 45 minutes ≈ 165 kcal.
Example 3 — Vigorous cycling, 85 kg, 20 minutes
MET for vigorous cycling ≈ 8.0. Calculation: 8.0 × 3.5 = 28; 28 × 85 = 2,380; ÷ 200 = 11.9 kcal per minute; × 20 minutes ≈ 238 kcal.
Reference MET values by activity
| Activity | Approx. MET | 60 kg / 30 min |
|---|---|---|
| Yoga, stretching | 2.5 | ~75 kcal |
| Walking, slow (~4 km/h) | 2.8 | ~84 kcal |
| Walking, brisk (~6 km/h) | 3.5 | ~105 kcal |
| Weight training, general | 3.5 | ~105 kcal |
| Cycling, moderate | 6.8 | ~204 kcal |
| Swimming, moderate laps | 5.8 | ~174 kcal |
| Elliptical trainer | 5.0 | ~150 kcal |
| Running, 8 km/h | 8.3 | ~249 kcal |
| Cycling, vigorous | 8.0 | ~240 kcal |
| Jump rope | 10.0 | ~300 kcal |
Calorie balance: burned is only half the picture
Weight change depends on the gap between calories eaten and calories used, not on exercise alone. One kilogram of body fat stores roughly 7,700 kcal, so a single 300 kcal workout — however satisfying — offsets only about 4% of that. This tool is best used to see how a workout compares to food (a "300 kcal run" against a "300 kcal snack"), or to track relative effort across sessions, rather than as a countdown timer to a specific weight goal.
Common mistakes and things to double-check
- Picking the wrong intensity tier. "Running" and "running fast" can differ by 3-4 MET — always match the pace option to how hard you actually worked.
- Forgetting the afterburn effect (EPOC). High-intensity intervals keep your metabolism elevated for a while after you stop; the MET formula only counts the active minutes, so very intense workouts are typically undercounted slightly by this and any MET-based tool.
- Treating the number as exact. MET values are population averages from lab studies. Your actual fitness level, muscle mass, terrain, and even the weather can shift your real burn by 15-25% in either direction.
- Mixing up kg and lb. Double-check the unit toggle before reading the result — entering 154 while the toggle is set to kg (instead of lb) will overstate the estimate dramatically.
What this calculator does not do
It does not measure your heart rate, VO2, or actual metabolic rate, and it does not account for age, sex, body composition, or fitness level — all of which shift real energy expenditure. It is not a substitute for a fitness tracker's sensor data, a metabolic lab test, or professional medical or nutritional advice. If you're managing a medical condition, pregnancy, or a specific weight goal, use this estimate only as a rough planning reference and talk to a doctor or registered dietitian about numbers that matter for your health.
Sources & further reading
- CDC Physical Activity — national guidance on weekly activity levels and intensity
- American College of Sports Medicine — exercise testing and MET-based energy expenditure standards
- American Heart Association — fitness recommendations and moderate vs. vigorous intensity
- National Institutes of Health — research on metabolism and energy balance
Frequently asked questions
What is a MET?
A MET (Metabolic Equivalent of Task) is the ratio of your energy use during an activity to your energy use at rest. Sitting quietly is 1 MET; an activity rated at 8 METs burns about eight times as much energy per minute. This calories burned calculator multiplies the activity's MET value by your body weight and time using the standard formula kcal = MET × 3.5 × weight(kg) ÷ 200 × minutes, so the answer scales with both how hard and how long you exercised.
Why does this differ from my smartwatch or running app?
A MET calculator uses population-average values for each activity, while a smartwatch adds your real-time heart rate, GPS pace and personal profile. Neither is exact — wearables typically run 10-30% off in validation studies. Treat this exercise calorie calculator as a quick, ad-free estimate for planning, not a lab measurement, and expect some gap from any device.
Why do calories differ by intensity for the same activity?
Because effort is what burns energy. Running at 10 km/h has a higher MET than a brisk walk, so it burns more per minute even though both are "on your feet." That is why this tool lists activities by intensity (slow vs brisk walking, moderate vs vigorous cycling): picking the option that matches your actual pace gives a far more accurate calories burned estimate.
How many calories equal 1 kg or 1 lb of body fat?
Roughly 7,700 kcal per kilogram of fat, or about 3,500 kcal per pound. So the ~300 kcal a typical workout burns is a fraction of a kilogram — sustainable fat loss comes from a steady daily deficit, not a single session. Use the food equivalents in this exercise calorie calculator to see how one workout compares to what you eat.
Is my weight sent to a server?
No. Every calculation in this calories burned calculator runs inside your browser, and your weight, activity and duration never leave your device. Your last entry is saved only to your browser's localStorage for convenience on your next visit, and you can clear it anytime by clearing site data.