How Many Calories Does Your Workout Burn?

Learn how exercise calorie burn is estimated with MET values, why trackers disagree, and how to use the number sensibly. Informational, not medical advice.

Updated 3 min read By CodingEagles
Free tool Calories Burned Calculator Calories burned for an activity, by weight and time. Open tool

It is satisfying to know how many calories a workout burned, but those numbers are estimates — and they vary a lot depending on how they are worked out. Understanding the method keeps you from over-trusting any single figure.

TL;DR — Pick an activity, enter your weight and time in the calories burned calculator for an estimate.

How the estimate works

The calculator uses MET values — metabolic equivalents — which rate how intense an activity is compared with rest. A MET of 8 means you are burning about eight times your resting rate. Multiply the MET by your body weight and the time you spend, and you get an estimate of calories burned. Heavier people and longer or harder sessions burn more.

Why trackers disagree

If your smartwatch shows a different number, that is expected. Wearables fold in your heart rate and personal profile, while a MET formula uses population averages. Neither is “the truth” — both approximate a value that genuinely varies with fitness, technique and body composition.

Use it as a rough guide

The most common mistake is to “eat back” every exercise calorie a tracker reports, then wonder why weight loss stalls. Because the numbers run optimistic, it is safer to treat exercise burn as a bonus rather than a license to eat more. Use the calories burned calculator to compare activities, and lean on your calorie deficit for the real plan.

Frequently asked questions

How is calorie burn estimated?
It uses MET values — a measure of an activity's intensity — multiplied by your body weight and the time spent. Heavier people and longer, harder sessions burn more.
Why does my watch show a different number?
Wearables use heart rate and personal data, so their estimate differs from a formula. Both are approximations — treat either as a ballpark, not an exact count.

Ready to try it?

Calories burned for an activity, by weight and time. Free, in-browser, and 100% private — your data never leaves your device.

Open the Calories Burned Calculator