PSI to ATM Conversion Calculator — Pounds per Square Inch to Atmospheres
Convert pounds per square inch (psi) to standard atmospheres (atm) for gas cylinders, diving, altitude and vacuum applications. 1 atm = 14.6959 psi. The calculator also shows bar, kPa and mmHg for completeness.
psi
1 atm = 101 325 Pa = 14.6959 psi
- 1
Convert to pascals
14.696 × 6,894.757 = 101,325.351 psi = 6,894.757 293 Pa (from pound-force and international inch definitions). - 2
Divide by 1 atm in pascals
101,325.35 ÷ 101,325 = 1.000003
How does this calculator work?
1 psi = 0.068046 atm; 1 atm = 14.6959 psi = 101.325 kPa = 1.01325 bar = 760 mmHg. Standard sea level = 1 atm = 14.696 psi. Multiply psi by 0.068046 to get atm, or multiply atm by 14.696 to get psi. For gauge pressures (psig), add 14.696 before converting.
Formula
How this is calculated
Both units measure absolute pressure. The pascal (Pa) is the SI base unit (1 N/m²), and all other units are defined through it. The standard atmosphere is defined exactly as 101 325 Pa. The pound per square inch is derived from the international pound-force (exactly 4.448 222 N) and the international inch (2.54 cm), giving 1 psi = 6 894.757 293 Pa. Dividing: 1 atm / 1 psi = 101 325 / 6 894.757 ≈ 14.696, so 1 psi ≈ 0.068046 atm.
Practical references: standard sea-level atmospheric pressure is exactly 1 atm = 14.696 psi. Scuba tanks are filled to roughly 200–300 bar ≈ 2 900–4 400 psi ≈ 197–296 atm. Tyre pressures (gauge) of 30–35 psi equal 2.04–2.38 atm above ambient — or about 3.04–3.38 atm absolute. Vacuum gauges often report in mTorr or Pa; altitude pilots use atm equivalents.
Important: this calculator converts absolute (not gauge) pressure. If your reading is gauge (psig), add 14.696 psi (1 atm) before converting to get the absolute value. Car tyre gauges, blood pressure cuffs and HVAC gauges all report gauge pressure.
Frequently asked questions
Exactly 1 atm = 101 325 Pa. One psi = 6 894.757 293 Pa, so 1 atm = 101 325 / 6 894.757 ≈ 14.6959 psi. The quick reference is 14.7 psi ≈ 1 atm.
psia (absolute) is measured from a perfect vacuum; psig (gauge) is measured above local atmospheric pressure (≈ 14.696 psia at sea level). Always add 14.696 to convert psig → psia before converting to atm. The calculator assumes absolute pressure (psia).
Scuba diving and gas cylinder ratings, atmospheric science, high-pressure chemistry, altitude calculations and aerospace all use atm. Engineers often use psi (US) while scientists prefer atm or Pa (SI), making this conversion a common real-world need.
Also known as
TG we-Calculate Editorial Team. (2026). PSI to ATM Conversion Calculator — Pounds per Square Inch to Atmospheres [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/psi-to-atm-conversion-calculator
TG we-Calculate Editorial Team. "PSI to ATM Conversion Calculator — Pounds per Square Inch to Atmospheres." TG we-Calculate. 2026. https://we-calculate.com/calculator/psi-to-atm-conversion-calculator.
TG we-Calculate Editorial Team, "PSI to ATM Conversion Calculator — Pounds per Square Inch to Atmospheres," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/psi-to-atm-conversion-calculator
@misc{wecalculate_psi_to_atm_conversion_calculator, title = {PSI to ATM Conversion Calculator — Pounds per Square Inch to Atmospheres}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/psi-to-atm-conversion-calculator}}, year = {2026}, note = {TG we-Calculate} }
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