Bike tyre pressure calculator
The right tyre pressure — or tire pressure, if you spell it the American way — comes down to three things: your weight, the tyre width and the tyre system. Enter them and the calculator gives you separate figures for front and rear, in psi and bar.
Front
67 psi
4.6 bar
Rear
73 psi
5.0 bar
A guide value derived from manufacturer curves, not a measurement. Check the maximum pressure of both tyre and rim, and work towards the figure that suits you.
Why the front runs lower than the rear
The front wheel carries less of your weight – roughly 40 % against 60 %. Running the same pressure at both ends makes the bike feel nervous and costs grip in corners. The calculator takes about 8 % off the front, and it uses the width that is actually fitted there: plenty of bikes run a narrower front tyre than rear.
Tubeless saves less than everyone claims
The widely repeated rule of thumb – “run 7 to 10 psi less with tubeless” – is not backed by anything. It comes exclusively from companies that sell tubeless. Work out what the manufacturers' own calculators actually do (SRAM/Zipp, Vittoria) and you land at around 2 %. That is what this page uses.
Hookless is a safety limit, not a recommendation
On a hookless rim nothing but the pressure holds the tyre in place – there is no bead hook. Exceed the ISO/ETRTO limit and the tyre can blow off the rim. The limit applies even when a higher maximum is moulded into the tyre. The calculator therefore caps hard, and says so when it does.
Mountain bike and gravel run far lower than a road bike
A mountain bike tyre at 2.4 inches carries the same rider on roughly four times the air volume, so it needs roughly a quarter of the pressure: think 20 to 25 psi (1.4 to 1.7 bar) rather than 73 to 86. Gravel sits between the two, around 30 to 44 psi (2.1 to 3.0 bar) depending on width. Pick the type of bike above and the calculator uses the curve that belongs to it — the same one the BikeCare app uses for your service intervals.
E-bikes: the difference is the weight, not the curve
An e-bike does not need a different calculation — it needs the same one with more weight on it. Motor and battery add somewhere between 6 and 10 kg depending on the build. Simply add those kilos to your own weight: the calculator works from the total system weight of rider, clothing and bike anyway. A 75 kg rider on a bike 8 kg heavier than usual enters 83 kg. The type of bike stays whatever suits the tyre: an e-gravel bike is gravel, an e-MTB is a mountain bike.
What the calculator cannot know
Surface, internal rim width, tyre model and your riding style all shift the figure. Treat the result as a starting point and work towards your own in steps of about 3 psi (0.2 bar): too little feels vague and squirms in corners, too much skips over small bumps instead of absorbing them.
What tyre pressure should I run on a road bike?
On 28 mm tyres at around 75 kg (165 lb) rider weight, the guide figure is roughly 73 psi (5.0 bar) rear and 67 psi (4.6 bar) front. Narrower tyres need more, wider ones less – 25 mm lands nearer 86 psi, 32 mm nearer 59 psi. The calculator above works it out for your numbers.
What tyre pressure should I run on a mountain bike?
Far less than you might think. On 2.4 inch tyres at around 75 kg (165 lb) rider weight, the guide figure is roughly 23 psi (1.6 bar) rear and 22 psi (1.5 bar) front. A 2.2 inch tyre lands nearer 25 psi, a 2.5 inch one nearer 22. Tubeless allows a little less again. Pick “Mountain bike” above and the calculator uses the MTB curve.
How often should I check tyre pressure?
About every two weeks. Inner tubes lose air through the material itself, and tubeless tyres do too – even without a puncture. Before a longer ride it is always worth reaching for the pump.
How much less pressure in the wet?
Around 10 %. The larger contact patch buys grip without a noticeable penalty in rolling resistance. Tick “Wet road” above and it is included.
Does the maximum printed on the tyre apply?
On hooked rims, yes. On hookless rims the lower ISO/ETRTO limit applies even when the sidewall says more – otherwise the tyre can come off the rim.
Should the front and rear tyres be different widths?
They do not have to be, but many bikes are sold that way – 30 mm front and 32 mm rear, for instance. Enter both widths separately and the calculator works out each wheel with its own.
Stop working it out from scratch every time
In BikeCare you set tyre width and system once per bike. The app remembers when you last checked and reminds you – alongside the chain, brake pads and everything else. The core stays free.
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