How to Convert Pascals to PSI (Pa to psi)
Pressure conversions are used for tyre pressure (psi or bar), blood pressure readings in mmHg and weather maps in millibars. This guide shows how to convert pascals into psi by hand, with examples and a quick-reference table.
The conversion
To convert pascals to psi, multiply the value by 0.0001450377. To go the other way, divide by the same number (or multiply by 6,894.757). Because the factor is tiny, scientific notation keeps the numbers manageable.
PSI = pascals × 0.0001450377
Worked examples
- 3 Pa = 0.000435 psi
- 12.5 Pa = 0.001813 psi
- 75 Pa = 0.010878 psi
Pascals to PSI table
| Pascals | PSI |
|---|---|
| 1 Pa | 0.000145 psi |
| 2 Pa | 0.00029 psi |
| 5 Pa | 0.000725 psi |
| 10 Pa | 0.00145 psi |
| 20 Pa | 0.002901 psi |
| 25 Pa | 0.003626 psi |
| 50 Pa | 0.007252 psi |
| 100 Pa | 0.014504 psi |
| 250 Pa | 0.036259 psi |
| 500 Pa | 0.072519 psi |
| 1,000 Pa | 0.145038 psi |
Common questions
Is Pa to psi exact?
The factors used here are the internationally defined values where they exist; results are rounded for display only.
How do I convert back?
Use the PSI to Pascals converter.
Mistakes to avoid
Rounding the factor too early
Using 3 instead of 3.28 for feet per metre introduces an error of almost 9% before you have started.
Multiplying when you should divide
Converting to a smaller unit gives a bigger number, and converting to a larger unit gives a smaller one. If your answer moves the wrong way, you have inverted the factor.
Dropping the units
A bare number without a unit is easy to misread later. Always write the unit with the result.
Background
A conversion table is handy for common values, but a calculator is faster and avoids interpolation errors for anything in between.
For everyday use, three or four significant figures are usually enough. Engineering, science and trade documents may need more, and rounding should happen only at the end of a calculation.
Writing the units next to every number while you work is the simplest way to avoid mistakes. If the units do not cancel to leave the one you want, the calculation is set up wrongly.
For any value, use the Pascals to PSI Converter or browse all pressure converters.
Run your own numbers: Pascals to PSI Converter