Enter your weight and tire width, that is it. Bike weight is prefilled, so overwrite it with your real one.
Recommended tire pressure
Disclaimer
This calculator provides non-binding, calculated recommendations as a starting point for finding your optimal pressure. Despite careful development, we make no warranty as to the correctness, completeness or currency of the calculations.
The limits from your tire and rim manufacturer always take precedence. Never exceed the maximum pressure and never go below a printed minimum, no matter what this calculator shows. If the rim’s maximum pressure is lower than the tire’s, the rim value applies. For hookless rims (tubeless straight side) one more thing applies: the recommended maximum depends on tire width, running from 72 psi (5.0 bar) at 25 to 29 mm down to 43 psi (3.0 bar) from 45 mm up. The full banding is further down this page. Use hookless only with tire and rim combinations approved by the manufacturer. Check your rim manufacturer’s compatibility list.
This calculator is built for road and gravel bikes without a motor. It only accepts a bike weight between 6 and 15 kg, so a pedelec does not fit in the first place. For e-bikes, follow the figures from your tire and rim manufacturer, and make sure both are approved for the higher system weight.
Check your tire pressure before every ride with a pressure gauge, not your thumb. You act on the calculated values at your own risk.
We are liable for damage arising from the use of this calculator only in cases of intent or gross negligence. This limitation does not apply to damage resulting from injury to life, body or health, or to claims under the German Product Liability Act (Produkthaftungsgesetz); in those cases we are liable under the statutory provisions. This is a courtesy translation; the German version of this disclaimer governs.
Background
Hookless limits: why 72 psi is not always the answer
Almost everywhere you read the same number: hookless, 72 psi maximum. That is only the 25 to 29 mm band, the road bike row. On gravel it does not hold. ISO 5775-1:2023 recommends maximum pressures, banded by nominal tire width:
- 25 to 29 mm: 72 psi (5.0 bar)
- 30 to 34 mm: 65 psi (4.5 bar)
- 35 to 39 mm: 58 psi (4.0 bar)
- 40 to 44 mm: 50 psi (3.5 bar)
- 45 to 54 mm: 43 psi (3.0 bar)
So a 40 mm gravel tire on a hookless rim should not see 72 psi, it should see 50 at most. That is a 30 percent difference, and most guides never mention it. The standard explicitly calls this a recommendation for the marking on the tire sidewall, not a hard limit: what binds you is always the lower of the tire sidewall print and the rim manufacturer’s approval. This calculator uses the banded limits. If your setup needs more pressure than the rim can take, it caps at the limit and marks the value “at the limit”, so it is clear that there is no headroom left. More than ten percent over the limit and there is no number at all, only a warning. At that point the pressure is not the problem, the combination is: a wider tire or a hooked rim.
Tubes or tubeless: what actually changes
With a tube this calculator adds 2 to 5 psi, depending on the surface. More on cobbles, less on smooth asphalt. The reason is not rolling resistance but pinch flats: in a snakebite the tube is crushed between rim and obstacle, and only pressure prevents that. Tubeless has no tube to crush.
Both setups therefore get their own minimum pressures. Latex and TPU tubes behave more like tubeless, so pick Tubeless for those.
Why the front wheel runs less pressure
On a road bike roughly 40 percent of the weight sits on the front wheel and 60 percent on the rear. The front therefore needs about 6 percent less pressure. That is not a detail for purists: the front wheel steers and brakes, which is where grip pays off most directly.
How this calculator works
No secret, here is the formula:
pressure (bar) = (A + B × system weight) / tire width^k × surface factor
Road: A = 87.4 B = 0.992 k = 1.09
Gravel: A = 240.5 B = 1.744 k = 1.35
Front wheel: × 0.94
Surface factor: rough × 0.90 normal × 1.00 smooth × 1.10
With a tube: + 0.35 / 0.25 / 0.15 bar (rough to smooth)The coefficients are fitted to the median of three commercial calculators, measured across 15 identical setups in August 2026. The worst deviation is 1.1 percent on the road and 1.6 percent on gravel. The inverse-width shape is not invented, it comes out of Frank Berto’s tire drop measurements.
What this calculator deliberately cannot do: MTB, fat bike and tubulars. Above 50 mm the sources diverge so far that any number would be a guess. Everything is calibrated for 700c. And the surface steps are the softest part of the model.
Frequently asked questions
What psi should a road bike with 28 mm tires run?
At 70 kg rider weight on normal asphalt roughly 64 psi (4.4 bar) rear and 60 psi (4.1 bar) front. At 85 kg it is about 70 and 65 psi. The calculator above is more precise, because surface and setup matter more than the last few grams of body weight.
Does system weight include the bike?
Yes, and you enter it in its own field. It comes prefilled with 9 kg for road and 10 kg for gravel, so overwrite it with your real one. It does not move much: between a 7 kg race bike and an 11 kg build there is about 1.5 psi. Your own weight goes in the field next to it, dressed as you ride. You can leave out bottles and tools, two full bottles move the result by less than 1 psi.
Can I run lower pressure with tubeless?
Yes, for one concrete reason: without a tube there is no snakebite. That moves the lower limit down. At the top end tubeless changes nothing, there the rim still decides.
What if my tire shows a different maximum?
Then the printed value wins. Always. If the rim maximum is lower than the tire maximum, the lower of the two applies. This calculator does not know your specific model, your sidewall does.
Why do I sometimes get no number at all?
Because the combination of tire width, rim type and weight is not permissible. It usually hits hookless rims with narrow tires or with a lot of system weight. In that case a wider tire or a hooked rim is the answer, not a lower number.