Formula, in Cardio Conditioning

Calories Burned Formula (MET)

MET stands for Metabolic Equivalent of Task: an activity's energy cost as a multiple of sitting quietly, where 1 MET is about 1 kcal per kg of body weight per hour. Multiply the activity's MET by body mass and hours to estimate calorie burn.

4 variables. Published Mar 12, 2026. Updated Oct 5, 2026. By AI Fit Hub.

Education, not medical advice. The result comes only from the published formula and your inputs. How we check our formulas.

Formula

calories = MET × mass_kg × hours

Variables

MET

Metabolic Equivalent of Task

Ratio of activity rate to resting rate. Walking 5 km/h ≈ 3.5 MET, jogging 8 km/h ≈ 8 MET, vigorous cycling ≈ 10 MET. Compendium values cover 800+ activities.

mass_kg

Body mass

Kilograms. Energy cost scales linearly with mass for weight-bearing activities.

hours

Duration

Exercise duration in hours (45 minutes = 0.75).

1 kcal/kg/h

Compendium convention

1 MET ≈ 1 kcal per kg per hour (3.5 ml O₂/kg/min). The ACSM oxygen form, MET × 3.5 × mass_kg / 200 per minute, assumes 5 kcal per litre of oxygen and lands about 5% higher.

Step by step

1

Look up the MET value for the activity in the Compendium of Physical Activities.

Moderate cycling at 19–22 km/h on level ground: 8.0 MET.
2

Multiply MET × body mass.

8.0 × 78 kg = 624 kcal per hour.
3

Multiply by the duration in hours.

624 × 0.75 h = 468 kcal.
4

For incline walking or running, choose the MET of the activity at that grade (or use the ACSM walking equation) rather than adding a percentage to a flat MET.

Walking 3.0 mph is 3.5 MET on the flat; the ACSM walking equation puts it near 7 MET at a 10% grade, so a fixed '2% per percent of incline' rule would badly understate it.

Worked example

78 kg adult, 45 minutes moderate cycling (8 MET)

Activity MET

8.0

Weight (kg)

Duration (min)

calories = 8.0 × 78 × 0.75 = 468 kcal

Roughly 468 calories, of which about 410 are above what resting would have burned. Wearables often report more or less, because they estimate from heart rate and motion.

Common variations

ACSM walking equation: VO₂ = 0.1·speed + 1.8·speed·grade + 3.5. More accurate at slow paces than a flat MET value.

Heart-rate-based formulas (Keytel) require HR + age + sex + mass — more individualized, requires a chest strap for accuracy.

Power-based estimates (cycling/rowing): calories ≈ watts × 3.6 × duration_hr ÷ 4.18 ÷ 0.24 efficiency.

Run the numbers next

Cardio Walking Calorie Calculator
Estimate calories burned from walking using speed, duration, body weight, and incline.
Nutrition TDEE Calculator
Estimate your daily energy expenditure with Mifflin-St Jeor + activity factors.

Sources

2011 Compendium of Physical Activities , Ainsworth BE et al. (Medicine & Science in Sports & Exercise)
ACSM's Guidelines for Exercise Testing and Prescription, 11th ed. , American College of Sports Medicine