Calories Burned Calculator

How Calories Burned Is Calculated

The calculator uses the MET (Metabolic Equivalent of Task) method, which is the standard in exercise science research. The formula is:

Calories = MET × body weight in kg × duration in hours

A MET of 1.0 represents the energy you burn at complete rest (sitting quietly). An activity with a MET of 8 burns 8 times as many calories as sitting still. Running at a moderate pace (6 mph) has a MET of approximately 9.8; walking at 3 mph is about 3.5.

Why Results Are Estimates

MET values are population averages. Your actual calorie burn can vary by 10–30% depending on fitness level, body composition, efficiency of movement, terrain, and environmental temperature. More fit individuals tend to burn slightly fewer calories for the same activity because their bodies become more efficient. Nevertheless, MET-based estimates are the most practical and scientifically grounded method available outside a metabolic lab.

Cardio vs. Strength Training

Cardio activities like running and cycling burn calories during the workout primarily. Strength training and HIIT burn fewer calories during the session but cause a measurable "afterburn" effect (excess post-exercise oxygen consumption, or EPOC) where your metabolism stays elevated for hours afterward. This afterburn is not captured in simple MET calculations.

Knowing your exercise calorie burn is particularly useful when using a calorie deficit calculator — if you exercise regularly, you may need to adjust your TDEE upward, or eat back some of those exercise calories, to avoid an unintentionally large deficit. The TDEE calculator factors in your overall activity level for a comprehensive daily calorie estimate.

Frequently Asked Questions

Does body weight affect calorie burn?

Yes — directly. A heavier person burns more calories performing the same activity because there's more mass to move. A 200-lb person running for 30 minutes burns roughly 25–30% more calories than a 150-lb person running at the same pace.

Are the MET values the same for everyone?

MET values represent the energy cost relative to resting metabolism for the average adult. For very fit athletes, some activities feel easier (lower perceived exertion) but technically still burn the same caloric rate per kg of body weight at the same external workload.

Do I burn more calories in the heat or cold?

Both extremes slightly increase calorie burn. In the heat, your body works harder to cool itself. In the cold, it generates heat to stay warm. In practice, the differences are small and rarely worth factoring in for general tracking purposes.

Can I use this to track weight loss?

Yes. One pound of fat represents roughly 3,500 calories of stored energy. A sustained caloric deficit of 500 calories per day — through diet, exercise, or both — leads to approximately one pound of fat loss per week. See the calorie deficit calculator to set a daily calorie target or the macronutrient calculator to optimize what you eat within that target.