PSI to Atmospheres (atm) Converter
A complete pressure unit conversion tool. Enter a value in any field to instantly convert between **PSI**, **Atmospheres (atm)**, **Bar**, **Kilopascals (kPa)**, and **Torr (mmHg)**.
How to Convert PSI to Atmospheres (atm)
Converting Pounds per Square Inch (PSI) to standard atmospheres (atm) is a common calculation in engineering, diving, and science. The conversion is based on the official definition of 1 atmosphere.
The Exact Formula
One standard atmosphere (1 atm) is defined as the average air pressure at sea level, which is equal to 101,325 Pascals. One PSI is defined as 6,894.757 Pascals. By dividing these, we get the exact factor:
To convert from PSI to atm, you **divide the PSI value by 14.6959**.
- Formula:
atm = PSI / 14.6959 - Example:
100 PSI / 14.6959 = 6.8046 atm
To convert from atm to PSI, you **multiply the atm value by 14.6959**.
- Formula:
PSI = atm × 14.6959 - Example:
2 atm × 14.6959 = 29.3918 PSI
The Key Difference: atm vs. bar
A common point of confusion is the difference between `atm` and `bar`. They are very close but **not the same**.
- 1 bar is defined as exactly **100,000 Pascals (Pa)**.
- 1 atm is defined as exactly **101,325 Pascals (Pa)**.
Therefore, 1 atmosphere is slightly larger than 1 bar (1 atm = 1.01325 bar). Our calculator includes both for accuracy.
Common Pressure Conversion Table
| Measurement | PSI (approx.) | Atmospheres (atm) | Kilopascals (kPa) |
|---|---|---|---|
| Standard Atmosphere | 14.696 psi | 1 atm | 101.325 kPa |
| Car Tire Pressure | 32 psi | 2.18 atm | 220.6 kPa |
| Residential Water Pressure | 50 psi | 3.40 atm | 344.7 kPa |
| Scuba Tank (Full) | 3000 psi | 204.1 atm | 20,684 kPa |
Frequently Asked Questions (FAQ)
What is the formula for PSI to atm?
The formula is: Atmospheres = PSI / 14.6959. For a quick estimate, you can divide the PSI value by 14.7.
How many PSI are in 1 atm?
There are **14.6959... PSI** (Pounds per Square Inch) in 1 standard atmosphere (atm).
Is 1 bar the same as 1 atm?
No. They are very close, but 1 standard atmosphere (atm) is slightly larger than 1 bar. 1 atm = 1.01325 bar.
Formula (LaTeX) + variables + units
','
1 atm = 14.695948... PSI
- No variables provided in audit spec.
- NIST — Weights and measures — nist.gov · Accessed 2026-01-19
https://www.nist.gov/pml/weights-and-measures - NIST — SI units — nist.gov · Accessed 2026-01-19
https://www.nist.gov/pml/owm/metric-si/si-units
Last code update: 2026-01-19
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