How to convert atmospheres to pounds per square inch
One standard atmosphere equals 14.6959 pounds per square inch, so multiply the number of atmospheres by 14.6959:
psi = atm × 14.6959
atm = psi ÷ 14.6959 (1 psi = 0.068046 atm)
Example: 2 atm → 2 × 14.6959 = 29.3919 psi.
Going the other way, divide by 14.6959, or multiply by 0.068046.
Everyday values
| Atmospheres | Pounds per square inch | For example |
|---|---|---|
| 1 atm | 14.6959 psi | sea-level air pressure |
| 2 atm | 29.3919 psi | about 10 m under water (absolute) |
| 3 atm | 44.0878 psi | about 20 m under water (absolute) |
When you need this conversion
One standard atmosphere is 14.696 psi. Divers count roughly one extra atmosphere for every 10 metres of seawater, so at 20 m the absolute pressure is about 3 atm (44 psi).
Standard atmosphere to pound per square inch conversion table
| atm | psi | atm | psi |
|---|---|---|---|
| 0.5 atm | 7.348 psi | 5.5 atm | 80.8277 psi |
| 1 atm | 14.6959 psi | 6 atm | 88.1757 psi |
| 1.5 atm | 22.0439 psi | 6.5 atm | 95.5237 psi |
| 2 atm | 29.3919 psi | 7 atm | 102.872 psi |
| 2.5 atm | 36.7399 psi | 7.5 atm | 110.22 psi |
| 3 atm | 44.0878 psi | 8 atm | 117.568 psi |
| 3.5 atm | 51.4358 psi | 8.5 atm | 124.916 psi |
| 4 atm | 58.7838 psi | 9 atm | 132.264 psi |
| 4.5 atm | 66.1318 psi | 9.5 atm | 139.612 psi |
| 5 atm | 73.4797 psi | 10 atm | 146.959 psi |
About the units
- Standard atmosphere (atm): exactly 101,325 Pa, the average air pressure at sea level.
- Pound per square inch (psi): one pound-force on one square inch, about 6,894.76 Pa.
Both are units of pressure. The conversion factor comes from the exact definitions above, so the calculator is exact; results are only rounded for display (up to six significant digits).
Frequently asked questions
How many pounds per square inch are in one standard atmosphere?
One standard atmosphere is 14.6959 pounds per square inch. One pound per square inch is 0.068046 atmospheres.
How do I convert atmospheres to pounds per square inch?
Multiply the value in atmospheres by 14.6959. To go back, divide by 14.6959.
What is 2 atm in pounds per square inch?
2 atm = 29.3919 psi.
What is 3 atm in pounds per square inch?
3 atm = 44.0878 psi.
Sources
- NIST Special Publication 811 (2008), Guide for the Use of the International System of Units (SI), Appendix B: conversion factors.
- NIST Handbook 44 (2024), Appendix C: General tables of units of measurement.
Last reviewed 5 October 2026. Results are estimates; see our disclaimer.