Free cycling calculator
Bike Tire Pressure Calculator
A starting front and rear pressure for your weight, your tires and rims, and the ground you ride on. In bar and psi, right here, with no account.
How the calculation works
Each tire’s pressure comes from the air it holds, estimated from its width, the inner rim width and the wheel size, and from the load it carries: you plus the bike, with a little more on the rear wheel. Wider tires and rims need less pressure; more weight needs more.
The ride style, surface, casing and rim then adjust it: lower for gravel, cyclocross and wet roads, with reinforced casings and on hookless rims; higher with thin casings, inner tubes and road tubulars.
Model and source
This calculator reproduces SRAM’s tire pressure model, the one in its AXS Tire Pressure Guide, with the same presets and checks: tire width against inner rim width (ISO), and the pressure limits of hookless rims. For the same setup, it suggests the same pressures. SRAM built it around its Zipp wheels, so on other wheels treat the result as a starting point.
Open SRAM’s tire pressure guideHookless rims and maximum pressures
Hookless rims (tubeless straight side) take only tubeless tires approved for them, and ISO limits their pressure to 5 bar (72.5 psi); with wider tires the limit is lower, and the calculator warns you when a pressure goes past it. Whatever any calculator says, the maximum printed on your tire or rim, whichever is lower, comes first.