How many calories did you burn?

What the Calories Burned Calculator Does

This calculator estimates how many calories you burn during physical activity using the MET method (Metabolic Equivalent of Task). You enter your body weight, choose an activity, and set the duration in minutes. It returns an estimate of energy expended in kilocalories (kcal), the unit people commonly call "calories."

It is useful for anyone tracking exercise for weight management, planning a workout, balancing food intake against training, or simply comparing how demanding different activities are. Athletes, dieters, coaches, and casual exercisers can all use it to get a quick, reasonable estimate without wearable devices.

How It Works: The MET Formula

A MET value describes how hard an activity is relative to sitting still. Resting equals 1 MET, which is roughly 3.5 milliliters of oxygen consumed per kilogram of body weight per minute. An activity rated at 8 METs burns energy about eight times faster than rest.

The calculator uses the standard formula:

Calories burned = MET x 3.5 x body weight (kg) / 200 x time (minutes)

The constant 3.5 is resting oxygen use, and dividing by 200 converts oxygen consumption into kilocalories (this assumes about 5 kcal burned per liter of oxygen). MET values come from the Compendium of Physical Activities, which lists hundreds of activities, from slow walking (around 2.8 METs) to running and vigorous cycling (10 METs or more).

Worked Example With Real Numbers

Suppose a person weighing 70 kg jogs at a moderate pace (about 7 METs) for 30 minutes. Plug the values into the formula:

Calories burned = 7 x 3.5 x 70 / 200 x 30

Step by step: 7 x 3.5 = 24.5; then 24.5 x 70 = 1,715; then 1,715 / 200 = 8.575 kcal per minute; finally 8.575 x 30 = roughly 257 kcal.

So that 30-minute jog burns approximately 257 calories. If the same person weighed 90 kg instead, the result scales up to about 331 kcal, because heavier bodies use more energy to move.

Factors That Affect Your Result

MET-based estimates are population averages, so your actual burn can differ. Several variables push the number up or down:

• Body weight: heavier people burn more for the same activity, which the formula already accounts for.
• Intensity: a brisk walk and a stroll share a name but have very different MET values, so pick the closest match.
• Fitness level: trained individuals are often more efficient and may burn slightly less than the estimate.
• Body composition: muscle is more metabolically active than fat, so two people of equal weight can differ.
• Terrain and conditions: hills, wind, heat, or carrying a load increase effort beyond the listed MET.

Tips and Common Mistakes

Use weight in kilograms; if you weigh yourself in pounds, divide by 2.205 first (for example, 154 lb = 70 kg). Mixing units is the most frequent error and inflates or deflates results badly.

Choose a MET value that reflects your real effort rather than the most flattering option. Also remember the formula already includes your resting metabolism for that period, so the figure represents total energy used, not extra calories on top of doing nothing.

Treat the output as an informed estimate, not a precise measurement. For weight goals, pair it with a consistent food log and track trends over weeks rather than trusting any single session number.