How to use the treadmill incline intensity converter
This page expresses the effect of raising the incline as a flat-ground speed rather than as calories. Choose your gait, enter speed, incline and body weight, and you get oxygen uptake and METs plus the speed you would need on the flat to reach the same oxygen uptake, summed up as one sentence: an incline at this speed equals so many mph on the flat.
The maths uses the ACSM metabolic equations. Walking is VO2 = 0.1×S + 1.8×S×G + 3.5 and running is VO2 = 0.2×S + 0.9×S×G + 3.5, where S is metres per minute and G is the grade written as a decimal. Your mph figure is converted to metres per minute internally, and a 5% incline becomes 0.05. The flat equivalent is found by setting the grade term to zero and solving for the speed that gives the same oxygen uptake. METs are oxygen uptake divided by 3.5 (current as of October 2026).
There are limits. The walking equation is validated at roughly 1.9 to 3.7 mph and the running equation above 5.0 mph, and the screen warns you outside those bounds; the flat equivalent it solves for can itself fall outside them. One report found the running equation read about 14.6% high against measured values in athletes. Downhill grades and holding the handrails are not covered, and calorie burn is not an output of this page.
Frequently asked questions
Because the grade term drops out and the equation becomes the flat-ground equation. It is a useful way to check that the conversion is wired up correctly.
This page is for intensity equivalence only. It stops at oxygen uptake, METs and the flat-ground equivalent speed, and does not output calorie burn.
No. The ACSM equations cover level and uphill walking or running and do not apply to negative grades. Entering a negative incline shows a message instead of a result.