What This Calculator Does
The Calories Burned Weightlifting Calculator estimates how much energy you expend during a strength-training session. It uses the widely accepted MET (Metabolic Equivalent of Task) method, which links the intensity of an activity to your body weight and the time you spend exercising. Weightlifting MET values typically range from about 3.5 for light effort to 6.0 for vigorous powerlifting.
How To Use It
Enter your body weight in kilograms, the duration of your workout in minutes, and pick an intensity level. The calculator returns the total calories burned plus a per-minute breakdown so you can compare sessions. Use "Light effort" for slow, controlled accessory work, "Moderate" for typical mixed gym sessions, and "Vigorous" for heavy compound lifting or circuit-style training.
The Formula Explained
The core equation is $$\text{kcal} = \frac{\text{MET} \times 3.5 \times \text{weight (kg)}}{200} \times \text{minutes}$$. The constant 3.5 represents resting oxygen uptake in millilitres per kilogram per minute, and dividing by 200 converts oxygen consumption into kilocalories. Multiplying by the MET value scales that baseline up to your chosen activity intensity, and multiplying by minutes gives the total for the whole session.
Worked Example
Suppose you weigh 80 kg and lift for 60 minutes at a moderate intensity (MET 5.0). Calories per minute = $$\frac{5.0 \times 3.5 \times 80}{200} = 7 \text{ kcal/min}.$$ Over 60 minutes that is $$7 \times 60 = \textbf{420 kcal}.$$
FAQ
Is this exact? No estimate is exact — actual burn depends on muscle mass, rest intervals, and effort. MET formulas give a solid, science-based approximation.
Why does intensity matter so much? The MET value scales the entire result linearly, so heavy, fast-paced lifting can burn nearly twice the calories of light, leisurely sets of the same duration.
Should I count rest periods? Enter the total time you were actively training. Long idle breaks lower your average MET, so for very rest-heavy sessions consider the lighter intensity option.
