Understanding This Calculator
Unlike generic MET-table calculators, this tool uses the American College of Sports Medicine’s actual metabolic equations, which model VO2 (oxygen consumption) directly from speed and incline grade — the same math exercise physiologists use in clinical stress testing.
The ACSM equations use different coefficients for walking versus running because the biomechanics — and therefore the oxygen cost per unit of speed and grade — differ meaningfully between the two gaits. This calculator automatically switches formula at 5 mph, ACSM’s standard walk/run threshold.
- S speed in meters/minute (mph × 26.8224)
- G grade as a decimal (incline % ÷ 100)
- VO2÷3.5 converts to METs
- kcal/min MET × 3.5 × weight(kg) ÷ 200
| Speed | Incline | Mode | METs |
|---|---|---|---|
| 3.0 mph | 0% | Walk | 2.5 |
| 3.5 mph | 5% | Walk | 5.4 |
| 6.0 mph | 0% | Run | 9.8 |
| 6.0 mph | 5% | Run | 12.7 |
Frequently Asked Questions
Why does the formula switch at 5 mph?
ACSM validated the walking equation only up to about 3.7-4 mph and the running equation from roughly 5 mph up — between those speeds, biomechanics vary by individual, so 5 mph is used as the standard cutoff.
Does incline really make that much difference?
Yes — the grade term is multiplied by speed, so at higher speeds even a small incline adds meaningfully to oxygen cost and calorie burn, which is why incline training is an efficient way to increase intensity without increasing speed.