How to Calculate Calories Burned: Exercise Guide
Estimate exercise energy expenditure with the MET formula. Learn what metabolic equivalents mean, convert body weight and duration into calories, and use realistic MET values for walking, running, cycling, and more.
How to Calculate Calories Burned
Knowing roughly how many calories an activity burns helps with training fueling, weight-management math, and comparing workouts. The most common public-health style estimate uses METs (metabolic equivalents) together with body mass and time.
These formulas estimate gross energy cost under average conditions. Wearables that use heart rate or movement sensors apply different models and can disagree — useful as trends, not courtroom precision.
What is a MET?
One MET represents resting metabolic energy expenditure, conventionally about:
1\ \mathrmMET ≈ 1\ \mathrmkcal · kg^-1 · h^-1
(also associated with roughly 3.5 ml O₂·kg⁻¹·min⁻¹ in exercise physiology). Sitting quietly is near 1 MET. Brisk walking might be ~3–4 METs; hard running can exceed 10 METs.
If an activity is listed at 8 METs, it costs about eight times resting metabolic rate for that period (as an average classification).
Core MET calorie formulas
Calories per hour:
\mathrmkcal/h = \mathrmMET × W_\mathrmkg
Calories per minute:
\mathrmkcal/min = \mathrmMET × \fracW_\mathrmkg60
Total calories for t minutes:
\mathrmkcal = \mathrmMET × W_\mathrmkg × (t)/(60)
Equivalently for T hours:
\mathrmkcal = \mathrmMET × W_\mathrmkg × T
Where W_\mathrmkg is body mass in kilograms.
Worked example: walking
Weight 70 kg, walking at about 3.5 METs for 45 minutes:
\mathrmkcal = 3.5 × 70 × (45)/(60) = 245 × 0.75 = 183.75 ≈ 184\ \mathrmkcal
Worked example: running
Weight 70 kg, running near 10 METs for 30 minutes:
\mathrmkcal = 10 × 70 × (30)/(60) = 700 × 0.5 = 350\ \mathrmkcal
Worked example: cycling
Weight 80 kg, moderate cycling at 6 METs for 1.25 hours:
\mathrmkcal = 6 × 80 × 1.25 = 480 × 1.25 = 600\ \mathrmkcal
Body weight in pounds
Convert pounds to kilograms first:
W_\mathrmkg = \fracW_\mathrmlb2.2046
Example. 165 lb → 165 / 2.2046 ≈ 74.8 kg. At 8 METs for 40 minutes:
\mathrmkcal ≈ 8 × 74.8 × (40)/(60) ≈ 398\ \mathrmkcal
Common MET values (illustrative)
Published MET tables (such as the Compendium of Physical Activities) list dozens of codes. Representative values for education:
Intensity, grade, wind, skill, and stop-and-go patterns move you between rows. A "6 mph run" MET assumes continuous running on level ground for an average adult — not a trail race with hiking segments.
Net vs gross calories
The standard \mathrmMET × \mathrmkg × \mathrmhours estimate is approximately gross expenditure during the activity (including the energy you would have burned at rest). Net exercise calories subtract resting cost for the same period:
\mathrmkcal_net ≈ (\mathrmMET - 1) × W_\mathrmkg × (t)/(60)
For the 70 kg, 10 MET, 30 min run:
\mathrmkcal_net ≈ 9 × 70 × 0.5 = 315\ \mathrmkcal
versus 350 gross. Food-label "calories burned" claims are often closer to gross or device-specific models — know which you are tracking.
Linking METs to oxygen cost
Because 1 MET ≈ 3.5 ml·kg⁻¹·min⁻¹ of oxygen:
\dotV\mathrmO_2 ≈ 3.5 × \mathrmMET\ \mathrmml· kg^-1· min^-1
At 10 METs, \dotV\mathrmO_2 ≈ 35 ml/kg/min — a hard but submaximal effort for many recreational runners, near everyday "vigorous" territory.
Building a weekly estimate
Sum sessions:
\mathrmkcal_week = Σ_i \mathrmMET_i × W × (t_i)/(60)
Example. 70 kg person:
- 3 × 40 min walks at 3.5 MET → 3 × 3.5 × 70 × 40/60 = 490
- 2 × 30 min runs at 10 MET → 2 × 10 × 70 × 0.5 = 700
- Total activity estimate ≈ 1,190 kcal for the week (gross, exercise periods only)
This excludes non-exercise activity thermogenesis (daily steps outside workouts).
Applications
Workout comparison. A 60-minute 4-MET hike vs a 30-minute 8-MET ride can be similar in MET-hours: both are 4 MET-hours for a given body weight.
Fueling endurance sessions. Long efforts at moderate METs accumulate large totals — plan carbohydrates accordingly for performance (sports nutrition specifics vary).
Weight-management math. A 3,500 kcal ≈ 1 lb body-fat rule of thumb is rough and incomplete; MET estimates help quantify activity but metabolism adapts.
Program design. Progress by increasing duration, MET level (intensity), or frequency — the formula shows each lever's effect linearly under constant assumptions.
Common mistakes
Using pounds directly in the kg formula. Convert mass first.
Picking an elite MET for a casual pace. Overstates burn.
Double-counting with a watch and a MET spreadsheet. Pick one primary tracker for trends.
Assuming the calorie number equals fat loss the same day. Energy balance unfolds over time; water and glycogen shifts dominate short scales.
Ignoring rest intervals. Circuit training MET depends on work:rest ratio; continuous-table METs overstate stop-and-start sessions.
Forgetting that heavier bodies burn more at the same MET. The formula is linear in body mass by design.
Frequently asked questions
Are MET calories accurate? They are population averages. Individual economy, efficiency, and fidgeting differ. Expect useful ballparks, not exact lab calorimetry.
Do strength workouts burn fewer calories than cardio? Often fewer during the session at moderate durations, but lifts have other benefits; some resistance sessions still land at 3–6+ METs depending on pace.
Should I eat back all exercise calories? Depends on goals and how much your tracker over/under-reads. Many people start by eating back a fraction if fat loss is the aim.
Is a MET the same for everyone? The definition is standardized; the true intensity of "jogging" is not. Choose the Compendium row that matches your pace and terrain.
How do incline and load change METs? Uphill walking, ruck packs, and soft sand raise energy cost — use higher MET codes or device HR models.
Why does my treadmill say something different? Machines and wearables use proprietary equations, sometimes including or excluding basal burn differently.
Summary
For duration t in minutes and body weight W in kg:
\mathrmkcal = \mathrmMET × W × (t)/(60)
Select a MET that matches intensity, convert weight units carefully, and prefer consistency over false precision when tracking progress. Net burn subtracts about 1 MET of rest if you need exercise-only figures.
Estimate activity calories with our Calories Burned Calculator.