Work out calories burned climbing stairs instantly with clear inputs, formula shown and shareable results.
Stair climbing is one of the few activities where the physics is straightforward: work equals weight times gravity times height. Human climbing efficiency is about 23%, so the metabolic cost is roughly four times the mechanical work. Twenty three-metre floors lifts a 70 kg body 60 m, needing 41 kJ of work and about 43 kcal of food energy.
Mechanical work
W = m x g x height
Metabolic cost
kcal = W / 4184 / 0.23 at 23% efficiency
This is an estimate from population-average equations, not a medical or diagnostic assessment. Individual results vary with genetics, training history and technique. Seek advice from a qualified coach or clinician before making significant changes to training.
Muscle converts chemical energy to mechanical work at roughly that efficiency; the rest becomes heat, which is why climbing makes you hot quickly.
Some - about a third of the ascent cost, since the muscles work eccentrically to control the descent rather than lifting anything.