How to Estimate Calories Burned by Activity Using MET Values

Every fitness watch, treadmill console, and gym app pretends to know exactly how many calories you torched. None of them really do. What they all start from, underneath the marketing, is a single number called a MET value and a formula you can run on the back of a napkin. Once you understand that formula, you stop treating the watch as an oracle and start treating it as one estimate among several.

This guide walks through what MET values are, the exact math, why a heavier person burns more for the same workout, and how to compare two exercises honestly instead of trusting whichever machine flatters you most.

What a MET Value Actually Means

MET stands for Metabolic Equivalent of Task. One MET is the energy your body spends sitting quietly and doing nothing — roughly 1 kilocalorie per kilogram of body weight per hour. That is your idle baseline.

Every physical activity gets rated as a multiple of that baseline. Slow walking sits around 3 MET, meaning it costs about three times your resting rate. A steady run lands near 8 MET. Jump rope hits 11 or 12. These numbers come from the 2011 Compendium of Physical Activities by Ainsworth and colleagues, a research table that measured real people doing real activities. It is the same reference Apple Health, Garmin, and Strava seed their baselines from, which is why those apps tend to land in the same ballpark even when the final numbers differ.

The key insight: a MET value describes the intensity of an activity, independent of who is doing it. The person and the clock are what turn that intensity into an actual calorie count.

The Formula

Here is the math, in the form you will see in any exercise physiology textbook:

calories per minute = MET × 3.5 × body weight in kg / 200

The 3.5 is the oxygen consumption (in milliliters per kilogram per minute) of one MET, and dividing by 200 converts oxygen consumed into kilocalories. Multiply by however many minutes you exercised and you have the total burn.

If you prefer thinking in hours, there is an even cleaner version that gives the same answer:

total calories = MET × body weight in kg × hours

Both forms are identical math. The per-minute version is handy when you log a session in minutes; the per-hour version is the one to use when you want a quick mental estimate. The calories burned calculator runs the per-hour form internally and converts your weight to kilograms first, so you can enter pounds or kilograms without doing the conversion yourself.

A Worked Example

Take a 70 kg person who goes for a run at a comfortable pace rated at 8 MET, for 30 minutes.

Using the per-minute formula:

calories per minute = 8 × 3.5 × 70 / 200
                    = 1960 / 200
                    = 9.8 kcal per minute

Over 30 minutes that is 9.8 × 30 = 294 kcal.

Check it against the per-hour formula: 8 MET × 70 kg × 0.5 hours = 280 kcal. The small gap (294 versus 280) comes from the 3.5 / 200 constants being a slightly rounded version of the simpler 1-kcal-per-kg-per-hour assumption. Both are correct to within the precision the estimate deserves — call it roughly 280 to 295 kcal for that run. Anyone promising you a number to the single calorie is selling confidence the underlying science does not support.

Why Heavier People Burn More

Look back at the formula and notice that body weight sits right in the middle of it as a multiplier. That is not an accident or a fudge factor — it is physics.

Moving mass costs energy. A larger body has more tissue to haul up every hill, more limb to swing through every stride, and a bigger frame to keep oxygenated. So for the exact same activity at the exact same intensity, a 90 kg person burns more than a 60 kg person, in direct proportion to their weight.

Run the 8 MET, 30-minute example again for a 90 kg runner: 8 × 90 × 0.5 = 360 kcal, versus 240 kcal for a 60 kg runner. Same pace, same clock, a 50 percent difference in calories, purely because of mass. This is why a generic "running burns 300 calories per half hour" claim is meaningless without a weight attached, and why any honest calculator asks for yours.

I learned this the hard way years ago. I dropped about 12 kilograms over a year, kept running the identical 5K loop at the identical pace, and could not work out why my weekly burn quietly shrank even though I felt fitter and faster. The answer was sitting in the formula the whole time: I was lighter, so each loop cost fewer calories to carry. Fitness went up; calories per session went down. The MET math predicted exactly that, and it stopped me from blaming a "broken" watch.

Comparing Exercises Fairly

The real payoff of MET values is comparison. Hold weight and time constant, and the MET number alone tells you which activity burns more.

For a 70 kg person with 30 minutes to spend:

Brisk walk (4 MET): 4 × 70 × 0.5 = 140 kcal
Leisure cycling (6 MET): 6 × 70 × 0.5 = 210 kcal
Steady run (8 MET): 8 × 70 × 0.5 = 280 kcal
Jump rope (11 MET): 11 × 70 × 0.5 = 385 kcal

Jump rope nearly triples a brisk walk for the same half hour. That is the kind of trade-off that is invisible until you put the numbers side by side, and it is exactly what the calculator's stacked-row view shows you: add one row per activity, set the same duration, and read the per-activity kcal columns next to each other.

Stacking rows is also more honest than reading one figure off a single machine. A real session might be 20 minutes of intervals plus 15 minutes of cool-down walking, each at its own MET. Sum those two rows and you get the whole workout's cost — not just the loudest part of it.

Treating the Number Honestly

A MET estimate is a population average, not a personal reading. The formula ignores your fitness level, heart rate, terrain, wind, and how efficiently you move, so real burn can drift 10 to 20 percent in either direction. Treat it as a planning baseline.

That margin matters most when you use the number to decide what to eat. Eating back the full estimated burn is the classic reason a deficit stalls — the estimate runs high, you eat all of it back, and the math you thought was working quietly isn't. Leave a buffer. If you want to turn a workout figure into a weekly plan, feed your numbers into the BMR calculator to anchor your resting baseline, then build the activity burn on top of it.

Used this way — as a fast, transparent estimate you understand rather than a black box you trust blindly — the MET formula is one of the most useful pieces of arithmetic in fitness. It takes three inputs you already know, and it tells you, within a sensible margin, what your effort actually cost.

Made by Toolora · Updated 2026-06-13