What is the correct tyre pressure for my car?

Check the sticker on the driver's door sill or fuel filler cap. Pressures vary by car and load — front and rear may differ. Typical pressures are 30-36 PSI (2.0-2.5 bar) for most family cars.

Should I check tyre pressure hot or cold?

Always check when tyres are cold (not driven for 2+ hours). Hot tyres read 4-6 PSI higher. If you must check when warm, add 4 PSI to your target pressure and recheck when cold.

What happens if tyre pressure is wrong?

Under-inflation causes faster wear on the edges, increased fuel consumption, and poor handling. Over-inflation wears the centre of the tread and gives a harsh ride. Both reduce grip and can be dangerous.

How often should I check tyre pressure?

Check tyre pressures at least once a month and before any long journey. Tyres naturally lose about 1-2 PSI per month. Always check when cold (before driving). Correct pressure improves fuel economy by up to 3%, extends tyre life, and ensures safe handling.

What happens if I overinflate or underinflate my tyres?

Underinflated tyres wear on the edges, increase fuel consumption by up to 10%, generate more heat, and can cause blowouts. Overinflated tyres wear in the centre, reduce grip, and give a harsh ride. Both affect braking distance and handling. Check and adjust to the manufacturers specification.

CarCalcs

Tyre Pressure Calculator

Convert tyre pressures between PSI, bar, and kPa.

Pressure Value

Tyre pressure reading from your gauge

Unit

Unit of measurement for the value entered

How We Calculate This

Converts between the three common tyre pressure units using standard conversion factors.

Conversion Factors

1 bar = 14.5038 PSI
1 bar = 100 kPa
1 PSI = 6.89476 kPa

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Actual figures may vary based on driving conditions, vehicle specifications, and other factors.