PSI to Bar: Tyre Pressure Without the Guesswork

Tyre placards in the US use PSI; European pumps read in bar; manuals often add kPa. They measure the same thing.

The conversions

1 bar = 14.5038 PSI = 100 kPa 1 PSI = 0.0689476 bar = 6.895 kPa

For roadside use, bar × 14.5 = PSI is close enough.

Common tyre pressures

Bar	PSI	kPa	Typical use
1.8	26.1	180	Small car, front
2.0	29.0	200	Compact car
2.2	31.9	220	Mid-size car
2.5	36.3	250	Loaded car / SUV
3.0	43.5	300	Van, laden
8.0	116	800	Road bicycle

Bicycle tyres run far higher than car tyres, which is why a car foot pump often will not reach road-bike pressure.

Gauge pressure versus absolute

Tyre gauges read gauge pressure — pressure above the surrounding atmosphere. A tyre reading 2.2 bar actually contains about 3.2 bar absolute, because atmospheric pressure adds roughly 1.013 bar. Weather forecasts, by contrast, quote absolute pressure in hectopascals (1 hPa = 1 mbar). Our pressure converter works in whichever units you enter; just do not mix gauge and absolute figures in the same sum.

Cold pressure is the specification

Driving heats the air inside a tyre, and pressure rises roughly 0.1 bar (1.5 PSI) for every 10 °C. Manufacturer figures always assume cold tyres — parked at least three hours, or driven less than 2 km.

Consequences:

• Never bleed air from hot tyres to "correct" a high reading.
• Winter pressure drops. A tyre set to 2.2 bar at 25 °C reads about 1.9 bar at −5 °C, which is why TPMS lights appear on the first cold morning.
• Check monthly; tyres lose 0.05–0.1 bar naturally each month.

Why it matters

Ten percent under-inflation increases rolling resistance measurably, wears the shoulders of the tread, and lengthens braking distances in the wet. Over-inflation wears the centre of the tread and reduces the contact patch.

Related conversions

• Bar to PSI
• kPa to PSI
• All pressure units