Tire pressure calculator
Enter your weight and tire width. You get front and rear pressure, a range from fast to comfortable, and see what other tire widths would need.
Range from comfort to smooth tarmac
Many riders run almost the same pressure front and rear. Within about 0.3 bar that is fine. The difference matters mainly with luggage or narrow tires, where the rear would otherwise risk pinch flats.
Treat the value as a starting point. Ride a few laps with 0.2 bar more or less and notice what feels better.
Other tire widths compared
Same weight and setup. Wider tires need much less pressure.
How mybikesetup calculates
The basis is Frank Berto's tire drop rule. In the 1980s he measured 50 road tires at different pressures and loads for Bicycling magazine. The best compromise between rolling resistance and comfort is reached when the tire compresses by about 15% of its width under load. Bicycle Quarterly found in its own roll-down tests that tires stopped getting faster at roughly this pressure.
What matters is the load on each wheel, not total weight. That is why front and rear are calculated separately. Berto calls 45/55 typical. Bicycle Quarterly measured 40/60 on a road bike and 35/65 with rear luggage.
Between Berto's data points we use a contact patch model calibrated to his values, which matches them exactly. Berto did not measure tires wider than 37 mm. There we extrapolate the model. That is our own derivation and not backed by measurements.
Berto's tires were tires of their time, with inner tubes. Supple modern tires compress more at the same pressure. Treat the value as a starting point, not an exact target. Tubes or tubeless does not change the calculation, but with tubes the risk of pinch flats rises at low pressure.
Other calculators, for example from Silca or SRAM, do not publish their formulas, so their values can differ.
Sources: Frank Berto, All About Tire Inflation · Jan Heine, Bicycle Quarterly · Bikeradar on the hookless limit
Choosing the right tire pressure
The right tire pressure depends mainly on two things: the load on the wheel and the width of the tire. Too much pressure makes the bike harsh and no faster on normal roads. Too little raises rolling resistance and the risk of pinch flats.
The calculator looks for the pressure at which the tire compresses by about 15% of its width under load. The rule comes from engineer Frank Berto, who measured 50 road tires to derive it.
Table by weight and tire width in the guide Tire pressure for road and gravel →
Common questions
What tire pressure for 28 mm tires?
With 84 kg total for rider and bike and the typical 45/55 distribution, about 4.4 bar front and 5.3 bar rear. With 32 mm it is 3.4 and 4.2 bar. The calculator above works it out for your weight.
Do wider tires need less pressure?
Yes, much less. At 84 kg the rear needs 5.3 bar with 28 mm but only 2.9 bar with 40 mm. At the same pressure a wide tire compresses less relative to its width. Berto measured at 100 psi that a 20 mm tire compresses by 18% of its width, a 32 mm tire by only 10%. So the wide tire needs less pressure for the same tire drop.
Less pressure front than rear?
Yes, because the rear wheel carries more load, usually 55 to 60 percent. Many riders still run almost the same pressure. Within about 0.3 bar that is fine. The difference matters with luggage or narrow tires.
How much pressure on hookless rims?
At most 5 bar, as set by ETRTO and ISO. If the calculation asks for more, a wider tire is the better choice.
Can I run lower pressure tubeless?
Yes, you have more room downwards. With tubes, low pressure risks pinch flats, where the tube gets trapped between rim and obstacle. Tubeless removes that risk, so you can lean towards the comfort setting. According to Silca the fastest pressure is the same for both. The sources give no reliable figure for how much lower tubeless can go.