PSI to Atmospheres Converter

PSI to Atmospheres

Convert psi (psi) to atmospheres (atm). Both measure force per area, and the conversion comes up in weather, automotive, diving work.

The Formula

`` atmospheres = psi × 0.0680459639099 psi = atmospheres × 14.6959487755 `

One psi is 0.068046 atmospheres, and one atmosphere is 14.6959 psi.

Conversion Table

PSI	Atmospheres
1 psi	0.068046 atm
2 psi	0.136092 atm
5 psi	0.34023 atm
10 psi	0.68046 atm
25 psi	1.7011 atm
50 psi	3.4023 atm
100 psi	6.8046 atm
500 psi	34.023 atm
1,000 psi	68.046 atm

The Other Direction

Atmospheres	PSI
1 atm	14.6959 psi
2 atm	29.3919 psi
5 atm	73.4797 psi
10 atm	146.9595 psi
25 atm	367.3987 psi
50 atm	734.7974 psi
100 atm	1,469.59 psi
500 atm	7,347.97 psi
1,000 atm	14,695.95 psi

What Each Unit Is

PSI (psi) — pounds-force per square inch, equal to 6,894.76 pascals. The imperial pressure unit, still standard for US tyres, plumbing and compressed air.

Atmospheres (atm) — exactly 101,325 pascals, by definition. The mean air pressure at sea level, adopted as a reference standard.

A Sense of Scale

• Car tyres run at 32–35 psi
• Household water is 40–60 psi
• Pressure doubles at 10 m underwater
• Everest’s summit is about 0.33 atm

Precision

The factor 0.0680459639099 is rounded. For engineering work carry more digits than the table above, and round only at the end — rounding at each step compounds.

In Code

`javascript const psiToAtmosphere = (value) => value * 0.0680459639099; ``

Where This Conversion Comes Up

• Weather
• Automotive
• Diving
• Aviation
• HVAC

How Many Decimals Do You Need?

Rounding the factor costs accuracy, and how much depends on the factor. Converting 137 psi with the factor truncated at each decimal place:

Decimals kept	Factor	137 psi becomes	Error
0	0	0	100.0000%
1	0.1	13.7	46.9595%
2	0.07	9.59	2.8716%
3	0.068	9.316	0.0675%
4	0.068	9.316	0.0675%

A rule that holds for any conversion: round once, at the end. Rounding the factor and then multiplying compounds the error through every subsequent calculation, while carrying full precision and rounding the final answer does not.

The right number of significant figures is set by your input, not by the converter. If you measured psi to three significant figures, the answer in atmospheres is only good to three — writing more digits claims precision the measurement never had.

Other Conversions From PSI

The same value in every other unit this converter supports for pressure:

From	To	Unit
1 psi	6,894.76 Pa	Pascals
1 psi	6.89476 kPa	Kilopascals
1 psi	0.0689476 bar	Bar
1 psi	51.7149 mmHg	mmHg

Chaining conversions works — psi to metres to feet gives the same answer as psi to feet — but each step rounds, so a chain of three conversions carries three roundings. Convert directly where a direct factor exists.