How do I calculate bicycle tire pressure?

Enter your total system weight (rider + bike + gear), tire width, rim type, and terrain. VeloPSI calculates separate front and rear PSI recommendations using empirically validated models calibrated against professional cycling data.

How does temperature affect bike tire pressure?

Temperature changes cause tire pressure to fluctuate approximately 1.5 PSI per 10°F (Gay-Lussac's Law). For the most accurate pressure, pump at the ride site or check pressure before riding.

What PSI should I run for tubeless tires?

Tubeless tires typically run 5–15% lower pressure than equivalent tubed setups at the same load. VeloPSI applies this discount automatically when you select a tubeless rim type.

What is the maximum PSI for hookless rims?

ETRTO 2020 standard sets hookless rim maximum pressure at 72.5 PSI for 25–29mm tires, decreasing to 43.5 PSI for 45–54mm tires. VeloPSI enforces these limits automatically and warns when you approach them.

Should front and rear tire pressure be different?

Yes. Rear tires carry more weight and need higher pressure. VeloPSI calculates front and rear independently based on your weight distribution, typically resulting in 10–20% higher rear pressure for road bikes.

Bicycle Tire Pressure Calculator

Name: VeloPSI
Author: VeloPSI

Rider + Bike + Gear

Combined total — rider, bike, kit, and any cargo

Width unit

Front Width

Rear Width

Wheel Size

Rim Type

Tire Casing

Reinforced casings support lower pressures by providing structural protection

Front Fork

Rigid: lower front pressure (tire does all suspension). Suspension: higher front + harder rear (fork handles impacts). MTB widths only.

Surface

Default: auto from tire width. Override for cargo, bikepacking, tandems, or unusual setups.

Front 41%

Rear 59%

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PSI / – bar

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PSI / – bar

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Save this setup →

Up to 5 bikes · stored on this device only

How to Use

Step 1. Enter your bike details — tire width, wheel size, system weight (you + bike + gear), and tube type. These are the foundation of your pressure calculation.

Step 2. Pick your bike type. This is about your bike's geometry and how it puts weight on the tires — not just what surface you ride on. A hybrid bike and a road bike can have identical tire widths but need different pressures because the rider's weight sits differently over each wheel. If you ride a hybrid or commuter and pick Road because you ride on pavement, your result will be off. Pick the type that matches your bike.

Step 3. Pick your terrain. This isn't about the name of the road — it's about what your ride actually demands of the tire. A paved rail trail and a rough chip-seal road are both "pavement" but they feel different under the tire. Pick the option that best describes the surface texture and conditions you actually ride.

Why VeloPSI

Most tire pressure calculators give you a single number based on weight and tire width. VeloPSI goes further. It calculates separate front and rear pressures because your front and rear tires carry different loads — and that difference matters. It also asks for your bike type and your terrain as two separate questions, because what your bike is and where you ride it aren't the same thing — a hybrid and a road bike with identical tires still need different pressure if the rider's weight sits differently over each wheel.

VeloPSI also accounts for fork suspension — something no other tire pressure calculator does. A rigid fork and a full-suspension fork demand completely different front tire pressures even on the same trail with the same rider. VeloPSI adjusts for that automatically when you select your fork type on gravel and MTB setups.

The model stays accurate across the full range of tire widths, from narrow road tires up through plus-size MTB rubber, instead of leaning on a single assumption that only holds for the middle of the range. Casing type is factored in based on how it actually affects the pressure a tire needs — not just its name on the box, since a tough puncture-resistant casing doesn't always mean a tire needs reinforced-casing pressure.

We also leave out anything that can't be measured reliably — there's no input asking you to guess your pump temperature, because that kind of false precision does more harm than good. Every recommendation is checked against real-world ride feel, not just theoretical models. Hookless rim safety limits are enforced automatically — you'll be warned before you get near a dangerous pressure. Tubeless setups get the appropriate pressure reduction built in. And it all runs offline, free, with no account required.

How It Works

VeloPSI uses a multi-factor pressure model validated against real-world ride data across road, gravel, and mountain bike setups. Narrow and wide tires follow different physics, and the model accounts for that continuously — there's no hard cutoff where a 45mm tire suddenly gets treated like an MTB tire. The transition is gradual and based on how tire behavior actually changes with width.

Front and rear pressures are calculated independently using weight distribution values that shift based on bike type and tire width. Terrain adjustments, casing type, tubeless discounts, and fork type are layered on top. The result is a recommendation that reflects how your specific setup actually behaves — not a generic chart lookup.

Modern research shows that lower pressures reduce rolling resistance on real roads by letting the tire absorb surface irregularities rather than deflecting off them. VeloPSI is built on this empirical approach, not the inflated numbers common in older cycling culture.

Fork suspension adjustment

For gravel and MTB setups, fork type is factored into both front and rear pressure. A rigid fork means the front tire does all the suspension work — that changes what pressure it needs. A full-suspension bike offloads rear impacts to the shock entirely. VeloPSI adjusts for each fork type so your pressures match how your bike actually absorbs the trail.

Hookless rims

Hookless rims have lower maximum pressure limits than traditional hooked rims, set by the ETRTO 2020 standard. VeloPSI enforces these limits automatically and warns you when your recommended pressure approaches the safe ceiling for your rim and tire combination.

Your data

All calculations run locally in your browser. Nothing is sent to any server. Bike profiles are stored on this device only.

Disclaimer

VeloPSI provides tire pressure recommendations as a starting guide only. Always follow your tire and rim manufacturer's guidelines — check the minimum and maximum pressure printed on your tire sidewall and never inflate outside that range. Manufacturer specifications take precedence over all calculator outputs. Ride conditions, rider skill, and equipment vary — always use your own judgment. The rider is solely responsible for all pressure decisions. VeloPSI and its authors accept no liability for any outcome resulting from use of these recommendations.