How to use the walking calorie calculator
- Enter your body weight in pounds or kilograms.
- Enter your average walking speed and how long you walked.
- Enter the incline as a percentage grade (the number shown on a treadmill), or 0 for level ground.
How the calculation works
The ACSM walking equation estimates oxygen uptake (VO₂) from speed and grade: a horizontal component (0.1 mL of oxygen per kg per meter walked), a vertical component (1.8 mL per kg per meter climbed) and a resting component (3.5 mL/kg/min, defined as one MET). Burning about 5 kcal per liter of oxygen consumed converts VO₂ to calories.
Gross calories include what your body would have burned at rest anyway; net calories subtract that resting component and better reflect the extra energy the walk cost.
Formula
- VO₂
- Oxygen uptake, mL per kg per minute
- S
- Speed in meters per minute (mph × 26.8224)
- G
- Grade as a fraction (5% = 0.05)
- 5
- Approximate kcal per liter of oxygen
Worked examples
160 lb person, 3 mph, 45 minutes, flat
Weight = 72.57 kg; speed = 80.47 m/min. VO₂ = 0.1 × 80.47 + 3.5 = 11.55 mL/kg/min (3.3 METs).
kcal/min = 11.55 × 72.57 ÷ 1000 × 5 = 4.19. Over 45 minutes ≈ 189 kcal gross, about 131 kcal net.
Same walk at a 5% incline
VO₂ = 8.05 + 1.8 × 80.47 × 0.05 + 3.5 = 18.79 mL/kg/min → about 307 kcal in 45 minutes.
Assumptions and limitations
- The equation was developed for walking speeds of roughly 50-100 m/min (about 1.9-3.7 mph). Outside that range it is less accurate.
- Individual differences in fitness, walking economy, body composition, terrain and carrying loads can change real energy use by 10-20% or more.
- Downhill walking is not modelled (grade must be zero or positive).
- This is a general estimate for information only, not medical or nutritional advice.
Frequently asked questions
How many calories does walking a mile burn?
Roughly 0.5-0.75 kcal per pound of body weight per mile at typical walking speeds (gross). A 160 lb person burns about 85-100 kcal per mile on flat ground.
Does walking uphill burn more calories?
Yes. Each percent of incline adds energy cost in proportion to speed. At 3 mph, a 5% grade increases calorie burn by roughly 60% compared with flat walking.
Why do fitness trackers show different numbers?
Devices use their own proprietary models, heart-rate data and assumptions about resting energy. Treat all such figures, including this one, as estimates.
Sources and references
- American College of Sports Medicine. ACSM’s Guidelines for Exercise Testing and Prescription (metabolic equation for walking).