The formula
kPa = psi × 6.894757293
Where the factor comes from — each unit by its definition, then its size in SI:
1 psi = lbf / in² = 6,894.75729317 Pa1 kPa = 1000 × Pa = 1,000 Pa
Dividing the two SI sizes gives the factor: 6.89475729317 (rounded for display; the underlying ratio is fixed by the definitions). The reverse factor is 0.14503773773.
Pressure is force per area; the pascal is one newton per square metre. Tyres are quoted in psi or bar, weather in hPa, blood pressure in mmHg and gas laws in pascals or atmospheres.
Worked examples
- A car tyre (US gauge): 32 psi = 220.632 kPa — 32 × 6.894757293 = 220.632
- Sea-level air (1 atm): 14.6959 psi = 101.325 kPa — 14.6959 × 6.894757293 = 101.325
- A car tyre (European gauge) (2.2 bar): 31.9083 psi = 220 kPa — 31.9083 × 6.894757293 = 220
- A systolic blood-pressure reading (120 mmHg): 2.32041 psi = 15.9987 kPa — 2.32041 × 6.894757293 = 15.9987
Frequently asked questions
How many kilopascals is 1 psi?
1 psi = 6.89475729317 kPa.
How do I convert kilopascals back to pounds per square inch?
Divide by 6.89475729317 — or multiply by 0.14503773773: 1 kPa = 0.14503773773 psi.