MET calculator

Turn any MET value into calories from your bodyweight and time, using the standard ACSM metabolic formula. Enter a Compendium MET, a machine-console figure, or pick an example — and see the gross-vs-net split and the reference-man band that one-box MET tools leave out.

How the math works

A MET (metabolic equivalent of task) is an activity's energy cost as a multiple of resting metabolism. One MET is defined as 3.5 mL O₂/kg/min of oxygen use, and oxygen releases about 5 kcal per litre, so a MET turns into calories with the standard metabolic constant (ACSM Guidelines, 2021). You bring the MET — from the Compendium of Physical Activities (Ainsworth et al. 2011), a machine console, or a lab test — and this does the two steps the activity-specific calorie pages do, with the activity table removed.

The net line strips the resting metabolism a MET already includes, using (MET − 1)/MET. That resting share is 1 / MET: a trivial 14% at a 7-MET effort, but a full 29% at 3.5 METs and 50% at 2.0. The lower the intensity, the more of the "calories burned" is just the clock. The 3.5 constant itself is a group average from one reference subject — see "When this calculator is wrong" for the band that puts around it.

Worked example

A 180 lb (81.6 kg) person holds a steady 7.0-MET effort — a brisk run, a hard elliptical session, vigorous cycling — for 30 minutes of active time.

• Oxygen cost: 7.0 × 3.5 = 24.5 mL/kg/min
• Per minute: 7.0 × 3.5 × 81.6 / 200 = 10.0 kcal/min (600 kcal/h)
• Session (gross): 10.0 × 30 = 300 kcal
• Session (net): the activity's own contribution is 257 kcal; the other ~43 kcal (14%) is resting metabolism

Now the band. Recompute the same session with Byrne et al.'s measured-mean resting baseline (2.6 mL/kg/min instead of 3.5) and the gross drops to 223 kcal — so the honest answer is a band of about 223–300 kcal gross, with the standard figure at the top. Drop the intensity and both effects grow: a 154 lb (69.9 kg) person doing general resistance training (3.5 METs) for 45 minutes burns 193 kcal gross but only 138 net — a 29% resting share — and the measured-mean baseline pulls the gross to 143 kcal. Round-number check: an 80 kg subject at 7.0 METs for 30 minutes is 294 kcal gross, 252 net. (MET-based calories are unit-agnostic — kcal is universal — so the only imperial/metric axis is the bodyweight input, lb ↔ kg.)

When this calculator is wrong

A MET-based calorie number is built on a constant measured from one man in the 1950s, and it's gross — so for the easy, low-intensity activities a generic MET calculator is mostly used for, it runs high twice over: once from the reference-man baseline, once from the resting metabolism it never subtracts. Both effects are largest exactly where this tool gets used most — light, everyday activities at low METs.

• It's gross, and the resting share grows as the effort eases. A Compendium MET counts the ~1 MET you'd have spent at rest. At a 7-MET run that's only 14% of the figure; at 3.5 METs it's 29%; at 2.0 METs it's a full 50%. For sizing what an activity added, read the net (MET − 1), not the gross.
• The 3.5 baseline is a reference man, not you. The "1 MET = 3.5 mL/kg/min" constant came from a single 70 kg, 40-year-old man. Byrne et al. (2005) measured resting VO₂ in 769 adults and found a mean of 2.6 mL/kg/min — so 3.5 overestimates actual resting VO₂ by about 35% on average (and ~20% for resting energy), with body composition explaining 62% of the spread. The over-read is biggest for heavier, older, higher-body-fat people, so read the standard number as the top of a band.
• A MET is blind to how you move. It can't see your economy, your terrain, grade, wind, or carried load — all of which move the real cost. Two people at the "same" MET don't cost the same.
• It assumes a steady, continuous effort. The MET prices a constant intensity, so clock time overstates a stop-start session. Count active minutes, and for intervals or heavy lifting — where heart rate and energy come apart — a MET table is the wrong tool.

What to do with the result

Use the number to plan, then let the scale calibrate it. For fitting an activity into your daily calorie budget, the gross, standard-baseline figure is the right one — those resting calories are real and are already counted on the intake side of your ledger, so subtracting them or shrinking the baseline would double-discount. Reach for the net figure only when you're isolating what a specific new activity adds — say, sizing the deficit from a daily walk you didn't do before.

Treat the headline as the top of a band, not a point. If you're heavier or carry more body fat, lean toward the measured-mean figure; if you're close to the lean reference build, the standard number is closer. Either way, the reference-man over-read is roughly a constant multiplier, so tracking the same activity week to week stays honest even when the absolute number is soft. Log your weight over two weeks against your intake and adjust by 100–200 kcal if it isn't moving as expected — your scale measures what any MET table only estimates.

Common questions

What is a MET?

A MET (metabolic equivalent of task) is how much energy an activity uses compared with sitting at rest. One MET is resting; a 7-MET activity uses about seven times the energy per minute. By convention 1 MET equals 3.5 mL O₂/kg/min of oxygen consumption, or roughly 1 kcal per kilogram of bodyweight per hour. The Compendium of Physical Activities (Ainsworth et al. 2011) assigns a MET value to hundreds of activities.

How do you calculate calories from METs?

Multiply the MET value by 3.5, by your bodyweight in kilograms, and divide by 200 — that's kcal per minute. Multiply by active minutes for the session total. For example, a 180 lb (81.6 kg) person at 7.0 METs burns 7.0 × 3.5 × 81.6 / 200 ≈ 10 kcal/min, or about 300 kcal in 30 minutes. The same formula written per hour is MET × weight(kg) × 1.05.

Is the MET calorie number gross or net?

The standard formula gives gross calories — it includes the resting metabolism you'd have spent anyway, because a MET is a multiple of rest. The net (the activity's own cost) uses (MET − 1). The resting share is 1 / MET, so it's small at high intensities (14% at 7 METs) and large at low ones (50% at 2 METs). For fitting a session into your daily budget, use gross; for sizing what it added, use net.

Why is the MET formula based on 3.5, and is it accurate?

The 3.5 mL/kg/min figure is the resting oxygen use of a reference subject — originally one 70 kg, 40-year-old man. It's a convenient standard, not a personal constant. Byrne et al. (2005) measured 769 adults and found resting VO₂ averaged 2.6 mL/kg/min, so 3.5 overestimates resting metabolism by about 35% on average, more for heavier or higher-body-fat people. Treat a MET-based figure as the top of a band, and your own weight trend as the real check.

What MET value should I use for my activity?

Look it up in the Compendium of Physical Activities (the research standard) — it lists values for hundreds of activities by intensity. The quick-pick list here holds a few common ones: a moderate walk is about 3.5, general resistance training 3.5, a 6 mph run 9.8. If a machine console shows a MET or you have a lab figure, enter that. Pick the intensity honestly: "moderate" and "vigorous" are different Compendium rows, not the same activity with a slider.

Are METs the same as calories?

No. A MET is an intensity — a ratio to resting metabolism — not an amount of energy. To get calories you combine the MET with your bodyweight and time, because a heavier person at the same MET burns more per minute. A MET value alone tells you how hard an activity is relative to rest; the calorie figure is MET × 3.5 × weight(kg) / 200 per minute.