Cycling Tire Pressure Calculator
Front and rear starting pressure
Match load, tire and riding surface
Result
Calculation summary
Enter values to see the result
Live wheel-load preview
Different loads need different pressures
Front
60 psi
Rear
73.3 psi
Load split
45/55
Front and rear pressures update independently from load split and measured tire width.
How to use this calculator
- 1Enter rider, bicycle and carried weight, then set the front load share.
- 2Measure inflated tire width and enter the lower maximum pressure allowed by tire or rim.
- 3Choose surface, tube setup, casing and weather, then test the result carefully.
Formula
psi = 1,230 × wheel-load kg ÷ width-mm² × surface × setup × casing × condition
A visible heuristic produces separate starting pressures; user-entered maximums are never exceeded.
Calculation steps
- Convert the total system mass to kilograms and split it by wheel.
- Scale pressure by measured width and chosen ride factors.
- Cap each wheel at its entered limit and show safety warnings.
Worked example
An 88 kg system with a 42/58 load split and 30 mm tires starts near 50 psi front and 69 psi rear before surface adjustments.
Assumptions
- Pressure is a starting estimate, not a structural limit.
- Actual inflated tire width is used.
- Loads are static estimates.
- Compatibility remains the user's responsibility.
Sources
Frequently asked questions
Why are front and rear pressures different?
The rear wheel usually carries more load, while tire widths can also differ.
Does tubeless always mean lower pressure?
It can permit a lower starting point because pinch flats are removed, but rim strikes and stability still matter.
Which maximum should I enter?
Use the lowest applicable maximum from the tire and rim documentation.
Is this safe for hookless rims?
Only after confirming the exact tire, rim and pressure compatibility with both manufacturers.