Road Bicycle
Tire Pressure Calculators

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.

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