A treadmill at 0% has no air resistance, which is why 1% incline is the usual recommendation. This tool uses the ACSM running equation to match energy cost between speed + incline and flat outdoor running.
Frequently Asked Questions
Why set 1% incline?
Research shows 1% grade reproduces the energy cost of outdoor flat running in calm conditions, offsetting the missing air resistance.
How exact is this?
It is the standard energy-equivalence approach; heat, humidity and running economy still change how it feels.
How much does incline change pace?
Each extra 1% of grade slows the equivalent pace by roughly 10–15 s/km, more at higher speeds.
Gear runners ask about
GPS running watch
Pace, laps and alerts on your wrist
Chest strap heart-rate monitor
More reliable than wrist-based HR
Race day running shoes
Lightweight shoes for tempo and race pace
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