Work out calories and kilojoules burned lifting weights, based on your body weight, session length, and how the session was structured — from technique work to a MetCon finisher.
Strength training calorie burn is estimated using a MET (Metabolic Equivalent of Task) value for the training style, multiplied by your body weight and the total session time — including the rest between sets. The formula is calories = MET × body weight in kilograms × time in hours. A 70 kg lifter doing a 45-minute hypertrophy session (moderate loads, shorter rest, MET 5.8) burns approximately 305 kcal, or about 1,274 kJ.
| Metric | Value |
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The calculation uses three inputs: your body weight, the total time you spent in the session (including rest between sets), and a MET value that represents how demanding that style of training is on average. Unlike a continuous-effort activity such as running, a lifting session alternates between hard working sets and rest — so the MET value assigned to each training focus already reflects the typical mix of work and rest for that style. That is why the duration you enter is the whole session, not just the time under the bar: the "averaging" is already built into the MET number.
The table below holds the training style fixed at a hypertrophy session (MET 5.8) for 45 minutes, so you can see how much body weight alone changes the total.
| Body Weight | MET | Calories (45 min) | Kilojoules |
|---|---|---|---|
| 60 kg | 5.8 | 261 kcal | 1,092 kJ |
| 70 kg | 5.8 | 305 kcal | 1,274 kJ |
| 80 kg | 5.8 | 348 kcal | 1,456 kJ |
| 90 kg | 5.8 | 392 kcal | 1,638 kJ |
| 100 kg | 5.8 | 435 kcal | 1,820 kJ |
Here body weight is fixed at 70 kg and duration at a full hour, so you can compare how much the training style itself changes the burn rate.
| Training Focus | MET | Work Density | Calories/Hour | Kilojoules/Hour |
|---|---|---|---|---|
| Technique / Rehab Block | 3.5 | ~35% | 245 kcal | 1,025 kJ |
| Heavy Strength Block | 5.0 | ~45% | 350 kcal | 1,464 kJ |
| Hypertrophy Session | 5.8 | ~55% | 406 kcal | 1,699 kJ |
| MetCon / Circuit Finisher | 7.5 | ~70% | 525 kcal | 2,197 kJ |
Resistance training — especially heavy compound lifting — leaves your metabolism running slightly hotter for a while after you rack the last weight. This is called excess post-exercise oxygen consumption (EPOC), or "afterburn": your body is still working to restore oxygen levels, clear metabolic byproducts and begin repairing muscle tissue. For a typical strength session this adds roughly an extra 6-15% on top of the session estimate above, with heavier, higher-intensity sessions (Heavy Strength Block, MetCon) trending toward the top of that range and lighter technique-focused work toward the bottom. It's a genuine bonus, but a modest one — worth knowing about, not worth building your whole calorie budget around.
Australian nutrition panels report energy in kilojoules rather than calories, so it helps to convert your session's calorie burn into the same unit. Multiply your kcal figure by 4.184 to get kJ. The 70 kg lifter in the worked example above, burning 305 kcal in a 45-minute hypertrophy session, has used about 1,274 kJ — a handy reference point next to the energy value printed on a protein bar, recovery shake or post-workout snack.
How many calories does strength training burn per hour?
It depends heavily on training focus. For a 70 kg lifter, a technique/rehab block (MET 3.5) burns around 245 kcal/hr, a heavy strength block (MET 5.0) around 350 kcal/hr, a hypertrophy session (MET 5.8) around 406 kcal/hr, and a MetCon/circuit finisher (MET 7.5) around 525 kcal/hr. Heavier lifters burn proportionally more at every intensity.
Is cardio or weights better for burning calories?
Minute for minute, high-intensity cardio (running, cycling, HIIT) usually burns more calories during the session itself than most strength training, because it keeps your body working continuously rather than cycling between sets and rest. Strength training's advantage shows up over time: building muscle raises your resting metabolic rate, and heavy or circuit-style lifting produces a larger afterburn (EPOC) than steady cardio. For overall calorie burn and body composition, a mix of both tends to outperform either alone.
Does strength training keep burning calories after the workout?
Yes. This is called EPOC (excess post-exercise oxygen consumption), or "afterburn." After a session your metabolism stays slightly elevated while your body restores oxygen stores, clears byproducts and repairs muscle tissue. For strength training this typically adds roughly 6-15% on top of the session's calorie estimate, with heavier and higher-intensity sessions (like Heavy Strength or MetCon) trending toward the higher end.
Why does this calculator use total session time including rest, not just time spent lifting?
Because the MET value assigned to each training focus already reflects how that style of training is typically performed, including its usual rest periods. A heavy strength block, for example, includes long rests between big compound lifts, and its MET (5.0) is lower than a MetCon session's MET (7.5) partly because of that lower work density. Multiplying MET by total session time already bakes the rest in — this differs from something like continuous running, where you're working the entire time and there's no rest component to account for.
How many calories does a 45-minute hypertrophy workout burn?
For a 70 kg lifter, a 45-minute hypertrophy session (MET 5.8, roughly 55% work density) burns about 305 kcal, or around 1,274 kJ. Of that 45 minutes, roughly 24.8 minutes is spent actually under load, with the rest as rest between sets and supersets.
Does body weight change how many calories lifting burns?
Yes. At the same hypertrophy intensity over 45 minutes, a 60 kg lifter burns about 261 kcal, while a 100 kg lifter burns about 435 kcal for the identical session. Because calories = MET × weight × time, a heavier body burns proportionally more for the same training.
What's the difference between the four training-focus presets?
They represent different combinations of intensity and rest. A technique/rehab block (MET 3.5, ~35% work density) uses light loads and long rests, typical of RPE 4-5 work. A heavy strength block (MET 5.0, ~45%) uses big compound lifts with long rests between heavy sets, RPE 7-9. A hypertrophy session (MET 5.8, ~55%) uses moderate loads with shorter rests and supersets, RPE 6-7. A MetCon/circuit finisher (MET 7.5, ~70%) keeps you moving almost continuously with minimal rest, RPE 8-10.
How do I convert calories burned strength training into kilojoules?
Multiply your kcal figure by 4.184, the standard conversion used on Australian food labels. The 70 kg, 45-minute hypertrophy example above (305 kcal) converts to about 1,274 kJ.