Calories Burned Calculator

Metabolic equivalents (METs) scale energy use against resting metabolism: sitting is 1 MET, so a 9.8-MET activity burns nearly ten times the resting rate. The standard conversion turns METs, duration and body mass into calorie estimates used across exercise science, and the activity values in this tool follow the Compendium of Physical Activities — the research reference that assigns MET levels from lab-measured oxygen consumption (running 6 mph at 9.8 METs, brisk walking near 5, hatha yoga near 2.5).

Estimates carry honest uncertainty. Fitness level, economy of movement and body composition shift individual results — two runners at identical pace can differ 20% or more, and fitter people burn fewer calories for the same task as their movement economizes. Use outputs to compare activities and size post-workout meals, not as lab measurements. Consumer wearables add their own layer: validation studies routinely find wrist trackers erring 20% or more against indirect calorimetry, usually overestimating — treat device numbers as motivational, not accounting.

Weight is the dominant lever because moving mass costs energy: the formula scales linearly with kilograms, so a 90 kg cyclist burns 20% more than a 75 kg rider at identical speed and duration. That linearity cuts both ways for weight loss — as you get lighter, the same workout burns less, which is one more reason loss stalls and targets need recalculation every few kilograms. Pair this tool with the calorie calculator: intake target on one side, expenditure estimate on the other, and the scale trend as referee.

Cardio versus weights is the wrong framing for calorie math. Per minute, running and cycling out-burn lifting by 2–3×, but resistance training preserves the muscle that keeps resting expenditure from collapsing during a diet — lifters who diet without training lose a quarter or more of each kilo as lean mass. The evidence-backed split for fat loss is a daily step base plus 2–4 weekly strength sessions plus whatever cardio you enjoy enough to repeat; adherence beats the theoretically optimal modality every time.

Afterburn (EPOC) is real but small and routinely oversold. Vigorous intervals elevate metabolism for hours afterward, yet measured EPOC typically adds only 6–15% on top of the session itself — a 400 kcal HIIT workout might net ~450, not 700. Marketers selling '48-hour burn' count on you never checking. Count the session, treat afterburn as a rounding bonus, and never eat back calories you merely hope EPOC provided.

Frequency and progression matter more than any single session's number. Three 300 kcal sessions weekly (900 total) reshape a month; one heroic 900 kcal Saturday followed by six sedentary days mostly produces soreness. When the weekly total plateaus, add 10% volume or one session before adding intensity — and when life compresses training time, protect frequency (short sessions) over duration, since the habit is what survives busy months.