Road Bicycle
Tire Pressure Calculators

Agile Compass logo
Rhône-Alpes France & Piedmont Italy
makes this page possible

“15% drop” method

Weight measured at wheel

lb. mm psi

Weight of (Fully-dressed) Rider & Bike

lb. mm psi mm psi

If calculated pressure exceeds tire’s rated maximum, choose a wider tire. If calculated pressure is below tire’s safe minimum, choose a narrower tire.

From Optimizing Your Tire Pressure for Your Weight by Jan Heine (or a more extensive version, “PSI RX” by Jan Heine, Adventure Cyclist magazine, March 2009).

This archive argues that the whole 15% drop premise is flawed.

Michelin logo Michelin Bicycle Tire
700c wheels

lb. mm psi
From this Michelin tire chart. Calculator obeys the chart’s min/max pressure limits.