Convert Pounds per Square Inch to Standard Atmospheres
Convert Pounds per Square Inch (psi) to Standard Atmospheres (atm) instantly and accurately.
Conversion Formula
atm = psi × 0.06804596391
About Pounds per Square Inch
One pound per square inch (psi) ≈ 6,894.76 Pa - the dominant pressure unit in US industry and consumer products. Car tyres: 32-36 psi; truck tyres 80-120 psi; bicycle road tyres 80-130 psi. Home water supply: 40-80 psi; residential maximum 80 psi per plumbing code. Compressed air tools: 90-150 psi. Steam autoclave sterilisation: 15-30 psi. The distinction between gauge (psig) and absolute (psia) pressure is critical: gauge pressure is relative to ambient; absolute = gauge + ~14.696 psi. 1 psi = 6,894.76 Pa.
About Standard Atmospheres
The standard atmosphere (atm) = exactly 101,325 Pa - defined by the 10th CGPM (1954) as the reference air pressure at sea level. Used to define STP (0°C and 1 atm) for gas law and thermochemistry. Chemical equilibrium constants (Kp), Henry's law solubility, and thermodynamic tables are tabulated at 1 atm. ISA aviation standard: sea-level 1 atm / 15°C, pressure halving every ~5.5 km. Diving physics: +1 atm per 10 m depth (fresh water) so 30 m = 4 atm absolute. Diamond formation in Earth's mantle: ~50,000 atm. 1 atm = 101,325 Pa.
Quick Reference Table
| Pounds per Square Inch (psi) | Standard Atmospheres (atm) |
|---|---|
| 1 psi | 0.068046 atm |
| 2 psi | 0.136092 atm |
| 5 psi | 0.34023 atm |
| 10 psi | 0.68046 atm |
| 25 psi | 1.70115 atm |
| 50 psi | 3.4023 atm |
| 100 psi | 6.8046 atm |