How this instrument works
Resistance training doesn't burn calories at the same rate as steady cardio — even a hard lifting session tops out lower on the MET scale than a moderate jog — but intensity still swings the estimate a lot within weight lifting itself. The Compendium of Physical Activities separates general light-to-moderate lifting (3.5 MET) from vigorous, effortful sessions built around compound lifts like squats and deadlifts (5.0 MET) and from competitive-style powerlifting or bodybuilding training (6.0 MET).
The gap between those three levels comes down to rest periods and continuous exertion. General lifting with typical rest between sets averages out to a lower MET because a meaningful chunk of your session is spent recovering, not lifting. Vigorous squat-and-deadlift work and powerlifting-style training push the average up because the sets themselves demand more from large muscle groups and rest periods tend to be used more purposefully rather than idly.
One limitation worth knowing: this formula, like the rest of the Compendium, measures energy cost during the activity itself. It doesn't add anything for excess post-exercise oxygen consumption (EPOC) — the modest calorie "afterburn" that follows an intense strength session — because that effect wasn't part of what the Compendium researchers measured. Treat the result as your session's estimated calorie cost while lifting, not your total calorie cost for the day.
- Select the effort level that matches your session — light-to-moderate, vigorous squats/deadlifts, or powerlifting/bodybuilding.
- Enter your body weight in kilograms.
- Enter your total session duration in minutes, including working sets but not a separately-counted warm-up.
- Read the estimated calories burned in kcal for that session.
- If your session mixes intensities — a light warm-up followed by heavy squats — run the calculator once per segment and add the totals.
Worked example — vigorous squats/deadlifts, 90 kg, 45 minutes
A 90 kg lifter doing a 45-minute session built around vigorous-effort squats and deadlifts (5.0 MET, Compendium code 02052): 5.0 x 90 x (45/60) = 5.0 x 90 x 0.75 = 337.5 kcal for that workout.
Compare that to a lighter, more typical hour-long session at general light-to-moderate effort (3.5 MET) for a 70 kg lifter: 3.5 x 70 x 1 = 245 kcal — a longer session at lower intensity lands in a similar range to a shorter, harder one, which is the trade-off intensity and duration make against each other in this formula.
Questions
Why does weight lifting burn fewer calories than running for the same time?
Because lifting involves substantial rest between sets and works muscles in short, forceful bursts rather than continuous movement, its average MET value over a full session is lower than steady-state cardio like running or cycling. General light-to-moderate lifting sits at 3.5 MET, versus roughly 7.5+ MET for a self-selected running pace — even though a single heavy rep can feel far harder in the moment, the per-minute average across a whole session tells a different story.
Does this calculator include the "afterburn" effect from heavy lifting?
No. Excess post-exercise oxygen consumption (EPOC) — the elevated metabolism that follows an intense strength session — isn't part of the Compendium's measured MET values, which reflect energy cost during the activity itself. A hard lifting session likely burns a bit more than this estimate once EPOC is factored in, but the Compendium doesn't quantify how much, so this calculator can't either.
Which intensity should I pick for a mixed strength-and-conditioning workout?
Pick based on what dominates the session. If it's mostly traditional sets and reps with standard rest, use light-to-moderate (3.5 MET) or vigorous squats/deadlifts (5.0 MET) depending on effort. If it's structured as continuous circuits with minimal rest, closer to CrossFit-style conditioning, you'll get a more accurate estimate from this site's burpee/calisthenics calculator instead, since that activity code better matches continuous high-effort work.
How should I estimate duration if I rest a lot between sets?
Use your total time in the gym for that session, including rest between sets — the Compendium's MET values for lifting were measured across sessions that include typical rest periods, so the rest is already priced in to the 3.5-6.0 MET range rather than something you should subtract out separately.
Is powerlifting really more calorie-intensive than general lifting?
According to the Compendium, yes — competitive-style powerlifting and bodybuilding training is rated at 6.0 MET, almost double general light-to-moderate lifting's 3.5 MET. That reflects heavier loads, more total sets, and typically less idle rest time in a structured powerlifting or bodybuilding program compared to a casual general-fitness lifting session.