How to estimate calories burned during weight training
Enter your bodyweight, not the weight on the bar. Time the training block from the start of your exercises to the finish, including normal rests between sets. Select the closest session category. Add only separate stopped time, such as a break away from training, in the extra-time field. Keep that field at zero if your training block already covers the full visit.
Choosing a realistic lifting intensity
General lifting is the starting point for mixed exercises at varied loads. A squat/deadlift block, vigorous bodybuilding session and resistance superset circuit have separate reference categories. Heavy weights alone do not establish the average energy cost of an hour. The category should describe the block as a whole; do not apply a vigorous rate to a long period of waiting between isolated attempts.
The formula and a worked example
Gross calories = MET × 3.5 × bodyweight in kg ÷ 200 × minutes. For 80 kg and 45 minutes of general lifting at 3.5 MET, that is 220.5 kcal. Add 15 minutes of stopped time at 1 MET for another 21 kcal: 241.5 kcal total. Resting energy for the full hour is 84 kcal, so the estimate above rest is 157.5 kcal. The result cards round these values to whole calories.
Why rest is handled this way
The training categories are reference activities, not measurements of each set. This calculator therefore does not multiply a lifting-only rate by seconds spent moving the bar. The optional stopped-time field is a transparent 1-MET assumption for time outside the block. Recovery metabolism can stay elevated, so this simple baseline does not measure recovery energy or an afterburn effect.
What this estimate can and cannot tell you
Use it to compare consistent session assumptions. It cannot measure your individual metabolism, assess workout quality or determine how many calories you should eat back. Technique, exercise selection, fitness and how the session is organized all matter. Sets, reps and total tonnage are useful training records, but they do not uniquely determine energy expenditure.