Pascals to PSI Converter

Pascals to PSI

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

The Formula

`` psi = pascals × 0.00014503773773 pascals = psi × 6894.75729317 `

One pascal is 1.4504e-4 psi, and one psi is 6,894.76 pascals.

Conversion Table

Pascals	PSI
1 Pa	1.4504e-4 psi
2 Pa	2.9008e-4 psi
5 Pa	7.2519e-4 psi
10 Pa	0.00145 psi
25 Pa	0.003626 psi
50 Pa	0.007252 psi
100 Pa	0.014504 psi
500 Pa	0.072519 psi
1,000 Pa	0.145038 psi

The Other Direction

PSI	Pascals
1 psi	6,894.76 Pa
2 psi	13,789.51 Pa
5 psi	34,473.79 Pa
10 psi	68,947.57 Pa
25 psi	172,368.93 Pa
50 psi	344,737.86 Pa
100 psi	689,475.73 Pa
500 psi	3,447,378.65 Pa
1,000 psi	6,894,757.29 Pa

What Each Unit Is

Pascals (Pa) — one newton per square metre — the SI derived unit of pressure. Named for Blaise Pascal, who established that pressure varies with altitude.

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.

A Sense of Scale

• Atmospheric pressure is 101,325 Pa
• A pascal is a very small unit
• Car tyres run at 32–35 psi
• Household water is 40–60 psi

Precision

The factor 0.00014503773773 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 pascalToPsi = (value) => value * 0.00014503773773; ``

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 Pa with the factor truncated at each decimal place:

Decimals kept	Factor	137 Pa becomes	Error
0	0	0	100.0000%
1	0	0	100.0000%
2	0	0	100.0000%
3	0	0	100.0000%
4	0.0001	0.0137	31.0524%

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 pascals to three significant figures, the answer in psi is only good to three — writing more digits claims precision the measurement never had.

Other Conversions From Pascals

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

From	To	Unit
1 Pa	0.001 kPa	Kilopascals
1 Pa	1.0000e-5 bar	Bar
1 Pa	9.8692e-6 atm	Atmospheres
1 Pa	0.00750062 mmHg	mmHg

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