Treadmill calculator.

How the numbers are worked out

Speed is converted to metres per minute (S) and incline to a fraction (G). The ACSM metabolic equations give oxygen use in mL per kg per minute:

1. Walking: VO2 = 0.1 × S + 1.8 × S × G + 3.5. Validated for about 50 to 100 m/min (1.9 to 3.7 mph).
2. Running: VO2 = 0.2 × S + 0.9 × S × G + 3.5. Validated above about 134 m/min (5 mph).
3. METs = VO2 ÷ 3.5. Calories = VO2 × body weight (kg) × minutes × 5 ÷ 1,000 (about 5 kcal per litre of oxygen). This is gross energy including resting.
4. Pace: 60 ÷ speed in km/h gives minutes per km; 60 ÷ speed in mph gives minutes per mile. Climb = distance × incline %.

Worked example. 6 mph (161 m/min), 2% incline, 70 kg, 30 minutes, running: VO2 = 0.2×161 + 0.9×161×0.02 + 3.5 = 38.6 mL/kg/min, 11.0 METs, about 405 kcal, 3 miles in 30 minutes, pace 10:00 per mile (6:13 per km), 97 m of climb.

Handrail use, a treadmill’s own calibration and your fitness change real results. Source (opened 2026-10-04): ACSM’s Guidelines for Exercise Testing and Prescription, 11th edition (2021), metabolic calculations.

FAQ

How many calories does a treadmill burn?

It depends on speed, incline and your weight. A 70 kg person running 6 mph at 2% incline burns roughly 13.5 kcal per minute by the ACSM running equation. Enter your own values above.

What is the pace for 6 mph?

6 mph is 10 minutes per mile, or about 6:13 per km. The calculator converts any speed on the console.

Does incline really change calories?

Yes. In the ACSM equations incline raises oxygen use in proportion to speed. For walking each 1% of grade adds 1.8 x speed to VO2.

Do I need 1% incline to match running outside?

Some studies suggest 1% offsets the lack of air resistance, but the ACSM equations used here do not add it. Enter 1% yourself if you want that adjustment.

Why does it warn about walking above 4 mph?

The walking equation is only validated up to about 3.7 mph. Above that, most people switch to a run or race-walk, and the equations can overestimate.