About

Correct tire pressure is one of the most significant yet overlooked factors in cycling performance and safety. Optimizing the air pressure in your tires balances three critical variables: rolling resistance, comfort (compliance), and traction (grip). Too high, and the bike bounces over imperfections, losing grip and speed. Too low, and you risk "pinch flats" or squirming tires during cornering.

This calculator estimates the ideal tire pressure using the "15% tire drop" principle—the pressure at which the tire compresses by 15% of its height under load. This level generally offers the optimal trade-off for most riding surfaces. The tool accounts for total system weight (rider + bike), tire width, and specific setup details like tubeless technology or wet conditions.

Formulas

The core calculation relies on determining the load on each wheel and applying a power law regression based on the tire's volume (width). The weight distribution is typically assumed to be roughly 40% on the front wheel and 60% on the rear for a standard road position.

Total Load = RiderWeight + BikeWeight
Front Load = Total Load × 0.42
Rear Load = Total Load × 0.58

Base Pressure (PSI) ≈ 153.6 × ( WheelLoad / Width^1.58 )

Adjustments are made for rim type (Tubeless systems generally allow for 10-15% lower pressure) and surface conditions (Wet or rough terrain requires reducing pressure by approximately 5-10% for better contact patch).

Reference Data

Tire Width (mm)	Terrain	Avg Front (PSI)	Avg Rear (PSI)
23mm	Road (Smooth)	90-100	95-110
25mm	Road (Mixed)	80-90	85-95
28mm	Road/Pavement	65-75	70-80
32mm	Commuting	50-60	55-65
40mm	Gravel	35-45	40-50
50mm (2.0")	XC / Trail	22-28	25-30
60mm (2.4")	Enduro / MTB	18-24	20-26

Frequently Asked Questions

The 'Max PSI' listed on a tire is a safety limit, not a recommendation. Riding at the maximum pressure often results in a harsh ride, increased rolling resistance due to vibration, and reduced cornering grip. The optimal pressure is usually significantly lower.

Tubeless tires eliminate the inner tube, removing the friction between tube and tire and reducing the risk of pinch flats. This allows you to safely run lower pressures (typically 10-15% less) to gain comfort and traction without sacrificing speed.

Yes. Reducing your tire pressure by about 5-10 PSI in wet conditions increases the contact patch area of the tire, improving mechanical grip on slippery surfaces.

The 15% drop is a widely accepted industry benchmark that maximizes the efficiency of pneumatic tires. However, personal preference, rim width, and specific tire casing stiffness also play a role. Use this calculator as a starting point and adjust by ±3 PSI based on feel.