MTB Tire Pressure Calculator
Enter your weight, tire width, and terrain to get a recommended front and rear pressure — the fastest way to stop guessing and start dialling in grip.
Pressure is the cheapest upgrade you own
Nothing changes how a mountain bike rides more than a few psi. Too much air and the tire pings off every rock and loses traction; too little and it squirms in corners and risks a pinch flat or a dented rim. The right pressure depends on your weight, your tire volume, and what you are riding — which is why a single number off the sidewall is never the answer.
Once you have a pressure you trust, pair it with the Wheel Size Converter to see how your tire and rim size change rollout, and the Suspension Sag Calculator to set the other half of your traction equation.
Frequently Asked Questions
Why do mountain-bike tires run so much lower than road tires?
A fat, high-volume MTB tire holds far more air, so it supports the same rider at a fraction of the pressure — and low pressure is exactly what you want off-road. A softer tire deforms around roots and rocks, keeps more rubber on loose ground, and takes the sting out of small hits. Where a road tire might run 80–100 psi, a trail tire is usually in the high teens to high twenties. The calculator works in that range, splitting the load slightly toward the rear because it carries more of your weight.
How does the calculator decide front and rear pressure?
It adds your kitted-up weight to the bike weight, then splits that load roughly 45% to the front tire and 55% to the rear — which is why it always suggests a little more air in the back. It scales an empirical pressure-per-pound figure inversely with tire width (a wider casing needs less air for the same footprint) and adjusts for terrain: more pressure on smooth, fast ground and less on loose, technical, or wet trails where grip and compliance matter most.
Should I run the same pressure with tubes and tubeless?
No. A tubeless setup has no inner tube to pinch-flat, so you can safely run several psi lower for extra grip and comfort — one of the main reasons riders convert. With tubes you need a little more air to avoid pinch flats (a 'snakebite') when the tire bottoms on the rim. The numbers here are a sensible tubeless-friendly starting point; add a couple of psi if you are still running tubes.
How should I fine-tune from the suggested pressure?
Ride the number, then adjust one tire at a time in 1–2 psi steps. If the tire feels vague, folds in corners, or you dent the rim or burp air, add pressure. If it skips over chatter and gives up grip, let a little out. Cold days, heavy mud, big drops, and rocky terrain all favour a touch more air. Never exceed the maximum pressure printed on your tire sidewall or rim.
A starting-point estimate for setting up your bike, not a safety specification. Never exceed the pressure printed on your tire or rim, and adjust for your own trails and feel.