How many calories do you burn during strength training?
Most people associate calorie burning with cardio. Treadmills, cycling, running. Strength training gets overlooked, and honestly, for good reason: it burns fewer calories than most cardio activities per hour. If pure calorie burn is what you're after, cardio wins.
But that doesn't mean calorie burn from strength training doesn't matter. And if you're trying to lose weight, strength training plays an important role that has nothing to do with calories: it helps you retain the muscle you've worked hard to build while you're in a calorie deficit. Losing weight without strength training means losing muscle along with fat, and that's not the outcome most people want.
So how many calories does strength training actually burn? The honest answer is: probably less than you think, and it depends on you specifically. Your body weight, age, height, sex, how long you train, and how hard you push all shift the number significantly.
I'll give you the real ranges, explain the math behind the estimates, and point you to our free calorie calculator so you can get a number personalized to you.
The short answer
Strength training typically burns between 180 and 600 calories per hour. That's a wide range, and here's why: a 60 kg woman doing a moderate 30-minute session will burn a very different number of calories than a 100 kg man doing an intense 60-minute workout.
Here are estimates for a standard resistance training session (8 to 15 reps per set, varied resistance, moderate effort) at different body weights and durations:
| Body weight | 30 minutes | 45 minutes | 60 minutes |
|---|---|---|---|
| 60 kg (132 lb) | ~130 kcal | ~195 kcal | ~260 kcal |
| 70 kg (154 lb) | ~160 kcal | ~240 kcal | ~320 kcal |
| 80 kg (176 lb) | ~190 kcal | ~285 kcal | ~380 kcal |
| 90 kg (198 lb) | ~225 kcal | ~340 kcal | ~450 kcal |
| 100 kg (220 lb) | ~260 kcal | ~390 kcal | ~520 kcal |
These numbers use the corrected MET method, which I'll explain below. They represent your total energy expenditure during the workout, including what your body would burn at rest during that same time.
For a personalized estimate based on your exact age, height, weight, and sex, use our calories burned calculator.
How the estimate is calculated
Most calorie calculators for exercise use something called MET, which stands for Metabolic Equivalent of Task. A MET value tells you how much energy an activity costs as a multiple of your resting metabolic rate. Sitting quietly is 1 MET. Walking is roughly 3 to 4 METs. Resistance training with moderate effort is rated at 3.5 METs according to the Compendium of Physical Activities.
The standard formula:
Calories = MET × weight (kg) × duration (hours)
For a 75 kg person lifting for 45 minutes at 3.5 METs: 3.5 × 75 × 0.75 = about 197 calories.
For a rough estimate, it works. But it has a flaw: the formula assumes everyone has the same resting metabolic rate. A 25-year-old and a 55-year-old with the same body weight don't burn the same number of calories at rest. Neither do a 160 cm and a 190 cm person. The standard MET formula ignores all of that.
The corrected MET method
This is the approach we use in RepCount and in our calorie calculator. Instead of assuming a universal resting metabolic rate, it first calculates your personal resting metabolic rate using the Harris-Benedict equation, which factors in your age, height, weight, and biological sex.
That personal RMR is then used to correct the MET value, producing a more individualized result.
The steps:
- Calculate your resting metabolic rate (RMR) using the Harris-Benedict equation
- Convert that into a rate per kilogram per minute
- Use your personal rate to adjust the standard 3.5 MET value for resistance training
- Multiply the corrected MET by your weight and workout duration
The difference isn't always dramatic, but it matters. For younger, taller, and heavier individuals, the standard formula tends to underestimate. For older or lighter individuals, it can overestimate. The corrected method accounts for those differences.
The full formulas are documented on our calculator page.
What actually affects how many calories you burn
The math gives you an estimate, but several real-world factors push the actual number up or down.
Workout duration is the most direct lever. A 30-minute session burns roughly half of what a 60-minute session does, all else being equal.
Rest periods matter more than most people realize. The 3.5 MET value for resistance training assumes a typical session with normal rest between sets. If you're resting 3 to 4 minutes between heavy sets as a powerlifter would, you're spending a lot of that hour sitting on a bench. Circuit-style training with 30 to 60 seconds of rest keeps your heart rate elevated and can push the effective MET closer to 5 or 6.
Exercise selection plays a role too. Compound movements like squats, deadlifts, and bench press recruit more muscle mass than isolation exercises like bicep curls or lateral raises. More muscle working means more energy spent.
Your body weight has a direct impact. Heavier people burn more calories doing the same activity because it takes more energy to move and support more mass.
Training experience is an interesting one. Beginners tend to be less efficient — their bodies use more energy to perform the same movements. As you get more experienced, your nervous system gets better at recruiting muscles efficiently, which can slightly reduce calorie burn for the same workout. The trade-off is that experienced lifters handle more volume and heavier weights, which compensates.
Intensity and load also contribute. Lifting heavier weights requires more energy per rep. But because heavier loads typically mean fewer reps and longer rest, the relationship between load and total calorie burn isn't straightforward. High-rep, moderate-weight training with shorter rest periods often burns more total calories per session than low-rep, heavy training.
Strength training vs. cardio for calorie burn
In a head-to-head comparison by the hour, most cardio activities burn more calories than strength training. Running at a moderate pace is roughly 7 to 10 METs depending on speed. Cycling can be 6 to 10 METs. Resistance training at moderate effort is 3.5 METs. If your only goal is to burn as many calories as possible in an hour, cardio is more efficient.
Where strength training becomes important is during weight loss. A calorie deficit means your body needs to get energy from somewhere, and without strength training, it will break down muscle along with fat. If you've spent months or years building strength, that trade-off isn't worth making. Strength training during a cut signals to your body that the muscle is still needed.
Building muscle also has a modest long-term effect on your resting metabolic rate. Muscle tissue burns more calories at rest than fat tissue does. The effect per kilogram of muscle is small, but it adds up over time.
For most people trying to lose weight, a combination of strength training and some form of cardio alongside a moderate calorie deficit is a practical approach. Strength training preserves your muscle. Cardio helps with the energy balance.
How accurate are calorie estimates for strength training?
I want to be upfront about this: there is no completely accurate way to track calories burned during strength training. Every number you see, whether it comes from a calculator, a smartwatch, or a gym machine, is an estimate. The corrected MET method is more personalized than a basic MET formula, but it's still built on averages and assumptions. Your individual metabolism, genetics, effort level, and exercise selection all affect the real number.
Treat any calorie estimate as a rough guide, not a precise measurement.
What about apps that calculate calories from your exercise data?
Some workout tracker apps claim to calculate calories burned based on the specific exercises, sets, reps, and weights you log. I'll be honest: I genuinely believe those numbers are made up. I've been building a workout tracker since 2013 and I have never seen a validated formula that can accurately convert "3 sets of 10 reps of bench press at 80 kg" into a reliable calorie number. The variables are too many. How fast did you perform each rep? How long did you rest? How efficient is your nervous system at that movement? No app has that data.
We could easily add a feature like that to RepCount. It would look impressive and people might like seeing a calorie number next to each exercise. But I'd rather give you an honest estimate based on a transparent, documented method than a precise-looking number I can't stand behind.
What about an Apple Watch or smartwatch?
Using a smartwatch in its strength training mode is a reasonable approach. It has an advantage that no calculator has: it measures your heart rate in real time. That gives it more data to work with than a formula based on body stats and workout duration alone.
In my own testing, the Apple Watch tends to give slightly higher calorie estimates than what RepCount calculates using the corrected MET method. I can't say whether that applies to everyone since Apple doesn't publish the exact formula they use. We do publish ours, and you can see every step of the calculation on our calculator page.
If you're wearing an Apple Watch or similar device during your workouts, that's a reasonable way to get a calorie estimate. Just know that those numbers are also estimates, not exact measurements.
The practical takeaway
Use calorie estimates as a directional tool. They're useful for comparing workouts over time and getting a general sense of your energy expenditure. They're not accurate enough to use as the sole basis for a precise calorie deficit.
What actually helps is tracking your workouts consistently. If you know your training volume is increasing over time (more sets, more reps, or more weight), you can be confident your calorie burn is trending up too, regardless of the exact number.
Get your personal estimate
Our calories burned calculator uses the corrected MET method to give you a more accurate estimate based on your age, weight, height, and sex. It takes about 10 seconds.
If you want this built into your training, RepCount calculates calorie estimates automatically for every workout using the same corrected MET method. On iOS, those estimates sync directly to Apple Health, so they show up alongside the rest of your health data without any extra steps. RepCount also logs every set and tracks your progression over time, so you can see how your training volume and effort change from week to week.