Tire Pressure Converter

Tire pressure is measured in three units depending on where you are: PSI in the US, bar in most of Europe, and kPa in some parts of Europe and Asia. All three measure the same thing — gauge pressure (pressure above atmospheric) — and convert with simple linear factors.

The formula

1 psi = 6.894757293168361 kPa   (exact NIST SP 811 definition)
1 bar = 100 kPa                  (exact SI definition)

psi → kPa: multiply by 6.8948
psi → bar: multiply by 0.068948
bar → psi: multiply by 14.5038
bar → kPa: multiply by 100
kPa → psi: divide by 6.8948
kPa → bar: divide by 100

Practical examples

Example 1 — US car spec is 35 psi. Convert for a European gauge: 35 × 0.068948 = 2.41 bar = 241 kPa.

Example 2 — European garage pump shows bar. Your car door placard says 220 kPa. The pump shows 2.20 bar — same value (kPa ÷ 100 = bar).

Example 3 — Bicycle tire. Road bicycle tires run 100–120 psi (690–827 kPa / 6.9–8.3 bar). Mountain bike tires run 25–35 psi (172–241 kPa / 1.7–2.4 bar).

Common mistakes

• Reading hot pressure instead of cold. Tire pressure rises 4–6 psi (28–41 kPa) after 20+ minutes of driving. Always check cold — before driving or after 3+ hours parked.
• Using the maximum pressure on the sidewall as the recommended pressure. The sidewall maximum is the tire's structural limit. Your recommended inflation is on the vehicle door jamb placard — always lower than the sidewall maximum.
• Different pressures front and rear. Many vehicles specify different pressures for front and rear tires due to weight distribution. Always check both.
• Not adjusting for payload or towing. When carrying a full load or towing, tire pressure often needs to be increased 3–5 psi above the standard recommendation. Check your owner's manual.

International and regional variations

Quick reference

For a full reference covering tire code segments, speed ratings, and load index values, see the Tire Size Chart: Speed Ratings & Load Index →.