Every workout burns calories, but the number depends on three things: how hard you work, how long you go, and how much you weigh.
About this calculator
Every workout burns calories, but the number depends on three things: how hard you work, how long you go, and how much you weigh. Heavier people burn more at the same pace because moving more mass takes more energy.
This calculator uses the standard MET formula from the Compendium of Physical Activities. MET (Metabolic Equivalent of Task) rates how much energy an activity uses compared to sitting still. Walking is about MET 3.5, running about MET 8, and cycling about MET 6. The math is simple: calories = MET × weight in kg × hours.
Use the result to plan post-workout meals, compare activities, or offset what you eat. A 70 kg person walking 30 minutes burns roughly 123 kcal; the same person running 30 minutes burns about 280 kcal. These are estimates — pace, hills, and fitness level shift the real number by 10-20%.
Pair this with the [[tdee]] calculator for your daily burn, the [[calorie]] calculator for intake targets, and the [[bmi]] calculator to track body composition. Runners can cross-check pace and distance with the [[pace]] calculator.
Common uses
- Estimating calories burned on a 30-minute morning walk before breakfast
- Comparing a cycling commute vs a brisk walk for the same 45-minute window
- Planning how much to eat after a gym session or weekend hike
- Logging workout energy for a calorie deficit or maintenance plan
- Teaching kids why running burns more calories than yoga in the same time
Frequently asked questions
What is a MET value?
MET stands for Metabolic Equivalent of Task. MET 1 is resting quietly. MET 3.5 is a moderate walk at about 5 km/h. MET 8 is a hard run. Higher MET means more calories burned per minute for the same body weight.
How many calories does a 70 kg person burn walking 30 minutes?
At MET 3.5, the formula gives 3.5 × 70 × 0.5 = 122.5 kcal, rounded to about 123 kcal. Brisk walking at MET 4.5 would push that to roughly 158 kcal for the same person and duration.
Are smartwatch calorie counts accurate?
Wrist devices often overestimate by 20-40% because they guess intensity from heart rate and movement. The MET formula gives a consistent baseline. Use your watch for trends and this calculator for a physics-based estimate.
Does fitness level change calories burned?
A fit person burns slightly fewer calories doing the same activity because their body runs more efficiently. The difference is usually under 10%. Weight and duration still dominate the result.
Should I eat back exercise calories?
If you track food closely, eating back half of what you burned is a safe starting point. Your [[tdee]] already includes light daily movement, so double-counting every walk can stall fat loss.