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Free tool

Tyre pressure calculator

Front and rear pressure in psi and bar for road, gravel, mountain, fat and e-bikes. Put in your weight, tyres and rim, and fine-tune the ride to suit you.

Fills in the internal rim width and wheel size for you.

What are you riding?

Include water, tools and the clothes you ride in. E-bikes: add the battery.

The size printed on the sidewall. A measured width on your rim is even better.

Wider rims support the tyre better, so allow a little less pressure.

This does not change the numbers. Tyre width and weight matter far more.

Surface

Good road surface

Tyre set-up

Tubeless can run lower: no tube to pinch.

Tyre casing

Most all-round tyres

Balanced. Firmer rolls a touch faster on smooth ground; softer grips and calms rough ground.

Your pressures

Front

62 psi

4.27 bar

Try 59 to 65 psi (4.07 to 4.48 bar)

30110 psi

Rear

67 psi

4.62 bar

Try 64 to 70 psi (4.41 to 4.83 bar)

30110 psi

What this means: Run about 62 psi in the front and 67 psi in the rear: a balanced set-up for a 28 mm tyre on smooth tarmac.

Safety. Never exceed the maximum pressure printed on the tyre sidewall or stated by the rim maker, whichever is lower. Check your tyres and rims before you inflate.

How to fine-tune

Start with these numbers. Drop 1 to 2 psi at a time (about 0.1 bar) until the tyre feels vague or squirms in corners, then go back up one step. If you feel every bump or the rim clangs on hits, add a little.

The wheel matters as much as the tyre. We build carbon wheels here in Rochford, and can help you pick a rim width to suit your tyres.

Book a wheel buildSee Nextie rims

Why tyre pressure matters

Tyre pressure is the cheapest change you can make to how a bike feels. Too high and the tyre bounces off small bumps instead of rolling over them, so you go slower on real roads and trails, lose grip in corners and arrive more tired. Too low and the tyre squirms, the rim can hit the ground, and with an inner tube you risk a pinch flat. The best pressure sits between the two, and it depends on more than most charts admit.

How this calculator works

It starts from a well-known rule: for the same amount of tyre squash under load, the pressure you need rises with the weight on the wheel and falls as the tyre gets wider, though not in direct proportion. Wider tyres carry the same weight on a lower pressure. We then adjust for the surface, tubeless or tubes, casing, rim width and how you want the bike to ride, and we split your weight between the front and rear wheels in the way that suits each type of bike. It is our own model, tuned against real set-ups, not a copy of anyone else's. Treat the answer as a very good starting point, then fine-tune it.

Tubeless or inner tubes

Tubeless tyres have no tube to pinch, so they can run around 8 to 10 per cent lower than the same tyre with a tube. That extra give smooths rough surfaces and adds grip without adding drag. If you ride tubes, the calculator raises the number to keep pinch flats at bay. If you are not sure whether to switch, our workshop videos cover setting up tubeless.

Rim width

The inside width of the rim shapes the tyre. A wider rim spreads the tyre out, gives it a broader base and more air volume, and lets it work at a slightly lower pressure. On road and gravel wheels that is about 2 to 3 per cent per millimetre. Pick one of our Nextie rims in the calculator and it fills in the width for you. Always check that your tyre is approved for the rim, using the tyre maker's chart.

Hookless rims and pressure limits

Hookless rims have no lip to hold the bead, so they rely on lower pressures. Road and gravel hookless rims are usually limited to about 5 bar (72.5 psi), and mountain bike hookless rims to about 2 bar (30 psi). Tick the hookless box and the calculator caps the answer and shows a warning. It does not replace the maximum on your rim and tyre, so read both, and never exceed the lower of the two.

How to fine-tune your pressure

Ride your usual loop at the calculated pressure. Then drop 1 to 2 psi at a time until the tyre feels vague or squirms in corners, and go back up one step. That is your ideal. If you feel every bump, or the rim strikes on hits, add a little. Change one thing at a time, note the numbers, and use the "Copy my numbers" button to keep them.

Typical pressures by discipline

These are rough starting points for an 80 kg rider, bike and kit, tubeless. Your own result will differ.

  • Road, 25 to 30 mm: about 55 to 75 psi (3.8 to 5.2 bar).
  • Gravel, 35 to 45 mm: about 28 to 42 psi (1.9 to 2.9 bar).
  • Mountain bike, 2.25 to 2.5 in: about 18 to 26 psi (1.2 to 1.8 bar).
  • Fat bike, 4.0 in: about 5 to 10 psi (0.3 to 0.7 bar), lower on snow and sand.
  • E-bike: a few psi higher than the same tyre on a normal bike, to carry the extra weight.

Need a wheel to suit?

The right tyre pressure starts with the right wheel. We hand-build carbon wheels in Rochford and can match rim width to your tyres. Book a wheel build or see the Nextie rims we can build with.

Tyre pressure questions

What tyre pressure should I run on a 28 mm road tyre?

For a rider, bike and kit weighing 80 kg on smooth tarmac, a tubeless 28 mm tyre on a 21 mm internal rim comes out at about 62 psi (4.3 bar) in the front and 67 psi (4.6 bar) in the rear. Heavier riders go up, lighter riders go down, and rough roads call for a few psi less. Use the calculator for your own weight and tyres.

Should I run lower pressure with tubeless tyres?

Yes. With no inner tube there is nothing to pinch against the rim, so tubeless tyres can run roughly 8 to 10 per cent lower than the same tyre with a tube. That is where the extra comfort and grip come from. The calculator applies this for you.

Does rim width change the pressure I need?

A little. A wider internal rim gives the tyre a broader, more stable base and more air volume, so you can run slightly less pressure, roughly 2 to 3 per cent per millimetre on road and gravel rims. It also changes the tyre's actual width, which is why pairing a tyre with a suitable rim matters.

What is the maximum pressure for a hookless rim?

Most hookless road and gravel rims are rated to about 5 bar (72.5 psi) and most hookless mountain bike rims to about 2 bar (30 psi). Check your rim maker's figure, because it is the limit that counts. The calculator caps its answer at these values when you tick the hookless box.

How do I know if my tyre pressure is too low?

The tyre feels vague or wallows in corners, the sidewalls squirm under hard cornering or braking, you get rim strikes on hits, or with tubes you suffer pinch flats. If any of those happen, add 1 to 2 psi. Too high feels harsh and skittery, and the bike gets bounced off line on rough ground.

Should the front and rear tyres have different pressures?

Usually yes, with the front a few psi lower. Most of your weight sits over the rear wheel, and a softer front tyre gives more grip and steering confidence. The calculator uses a different weight split for each type of bike.

How often should I check my tyre pressure?

Before every ride if you can. Tubeless tyres seep air over days, and inner tubes lose pressure faster than most people expect, especially latex ones. Use a proper gauge on your pump, because the numbers on cheap pumps can be well out.

Is the number on the tyre sidewall what I should pump to?

No. The sidewall figure is a maximum for safety, not a recommendation. Most riders are happier well below it. Never go above the sidewall or rim maximum, whichever is lower.

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