Bike tyre pressure calculator.

For a typical 70 kg rider on smooth tarmac with 28 mm tubeless road tyres, expect roughly 65–72 psi rear and 60–67 psi front. Heavier riders, narrower tyres or rougher chip-seal surfaces push pressure up; wider tyres and tubeless casings drop it down. Use the calculator above for an exact figure for your setup, or read our road bike tyre pressure guide.

Most gravel riders on 40 mm tubeless tyres run between 28 and 40 psi depending on surface and weight. Smooth hardpack tolerates higher pressure; loose, chunky or muddy gravel rewards lower pressure for grip and comfort. The calculator factors in surface so you don't have to guess, or see our gravel bike tyre pressure guide for full recommendations.

Yes — system weight (rider + bike + kit) is the single biggest input. Every extra 10 kg adds roughly 5–7 psi to the recommended rear pressure on the same tyre. Under-inflating for your weight risks pinch flats and rim damage; over-inflating costs grip and comfort.

ETRTO and most rim manufacturers cap hookless rims at 72.5 psi (5 bar). Above that pressure the tyre bead can blow off the rim. If the calculator recommends above 72 psi, fit a wider tyre rather than over-inflating — and always check the rim manufacturer's stated maximum. Read more in our hookless rim pressure limits guide.

Tubeless setups can typically run 8–15% lower pressure than the same tyre with a butyl tube because there's no risk of pinch-flatting an inner tube against the rim. Latex tubes sit somewhere in between. The calculator's casing selector accounts for this. Read the full tubeless vs tubed comparison.

Most riders carry about 53% of their weight on the rear wheel and 47% on the front (more biased on gravel). The rear is doing more work supporting load, so it needs more pressure. Equal front/rear pressures give a harsh, twitchy front end and a wallowing rear.