Power Output Climbing Stairs Calculator
Estimate the mechanical power you produce climbing stairs from your mass, the height gained and the time taken.
How it works
height = steps × rise · work = m·g·height · power = work ÷ time
Climbing stairs converts your effort into gravitational potential energy, m·g·h, and power is simply that work divided by the time you take. This is the mechanical power delivered against gravity — a classic gym-class fitness test — and it ignores the extra metabolic energy your muscles burn as heat, which is several times larger. A brief sprint up a flight can momentarily produce close to one horsepower.
Worked example
A 70 kg person climbs 20 steps of 0.18 m each (3.6 m total) in 8 s with g = 9.81: work = 70 × 9.81 × 3.6 ≈ 2472 J, so power = 2472 ÷ 8 ≈ 309 W, about 0.41 hp — roughly 4.4 W per kilogram of body mass.
Sources: Power (physics) — Wikipedia
Frequently asked questions
Is this the same as the calories I burn on stairs?
No. This is the mechanical power delivered against gravity. Your body is only about 20–25% efficient, so the metabolic energy you actually expend — and the calories burned — is several times larger than the mechanical work shown here.
Why does time matter so much?
Power is work per unit time. Climbing the same flight twice as fast doubles the power even though the work done against gravity is unchanged, which is why speed is the key variable in stair-climb power tests.
What is a typical stair-climbing power output?
A healthy adult sustains a few hundred watts up a flight, and a hard effort can briefly approach 700–750 W — around one horsepower. Trained athletes exceed this for short bursts.
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This calculator is for educational purposes. Double-check important results before acting on them.