Training / Tyres
Bike Tire Pressure Calculator: Front and Rear PSI for Your Weight
Work out the best bike tyre pressure for your weight and tyre width, separately for the front and rear wheel, based on Frank Berto's 15% tyre drop measurements, in psi and bar, for road, gravel, and touring tyres from 20 to 44 mm.
Bike Tire Pressure Calculator: Front and Rear PSI for Your Weight: The weight on each wheel is worked out from your total weight and the bike's front-to-rear split, then turned into the pressure at which the tyre compresses by 15% of its height, from the lines Frank Berto measured and Bicycle Quarterly published for 20 to 37 mm tyres. For 100 kg on a bike split 45/55, a 37 mm tyre needs about 45 psi in front and 53 psi at the rear; a 20 mm tyre needs about 125 and 155. Widths up to 44 mm extend the trend and are marked as estimates. Runs 100% locally in your browser with zero server file uploads.
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These are the pressures at which the tyre compresses by 15% of its height under load, from Frank Berto's measurements as charted by Bicycle Quarterly: below that, tyres roll more slowly; above it, the ride gets harsher with no gain in speed. Wheel loads come from your total weight and the bike's front and rear split. Use the tyre's real width, measured on your rim. Never go above the maximum printed on the tyre or the rim; for tubeless and very rough roads, a little lower is fine.
Measure the width
The same tyre measures wider on a wide rim. Measure the inflated tyre with a calliper and use that number rather than the one printed on the sidewall.
Limits
Never exceed the maximum pressure printed on the tyre or the rim, whichever is lower; hookless rims are often limited to about 5 bar (72 psi).
How to use it
- Enter the total weight of rider, bike, and luggage.
- Enter the real width of your tyres and choose the kind of bike.
- Pump the front and rear tyres to the pressures shown.
Privacy & limitations
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Frequently asked questions
Why is the rear pressure higher?
Most of your weight sits over the back wheel, typically about 60% on a road bike, so the rear tyre needs more air to deflect by the same amount.
Isn't harder always faster?
No. Above the pressure for about 15% drop, the tyre stops rolling noticeably faster on real roads, while the bike vibrates more, which costs energy and comfort.
What about mountain bike tyres?
The measurements stop at 37 mm. Wide off-road tyres run at much lower pressures chosen for grip, so start from the tyre maker's advice instead.
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