Calculator
What the Bar Converter does
Bar Converter: 1 bar = 14.50377377 psi, so multiply a bar value by 14.50377377 to get pound per square inch, or divide to go back. Example: 1 bar = 14.50377377 psi.
Enter Value, From and To and the Bar Converter reports Result, How it was calculated and Reverse conversion. You can nudge a single number and watch the effect straight away.
Most people who open the Bar Converter are anyone working across two measurement systems. Having the exact factor matters more than a rough mental estimate.
There is no account, no upload and no server round trip, because the page does the work itself.
The meaning of each field, the formula in use, and a worked example that starts from the default inputs are all further down.
What do the Bar Converter fields mean?
The Bar Converter uses 3 inputs. You do not have to fill everything in before seeing an answer; the starting values already produce one.
| Field | What to enter | Default |
|---|---|---|
| Value | required | 1 |
| From | choose from Pascal (Pa), Hectopascal (hPa), Kilopascal (kPa), Megapascal (MPa), Bar (bar) or Millibar (mbar) | Bar (bar) |
| To | choose from Pascal (Pa), Hectopascal (hPa), Kilopascal (kPa), Megapascal (MPa), Bar (bar) or Millibar (mbar) | Pound per square inch (psi) |
How does the Bar Converter work?
Both units are converted through pressure's base unit (Pa), so any of the 12 units in the dropdowns can be paired in either direction without loss of accuracy.
Definitions are taken from the SI system where one exists, and from CODATA or the IAU where a unit is established by measurement. No factor is rounded before the calculation.
Worked example
These are the values the Bar Converter loads by default, and the result it produces from them. This is the worked example the page starts from, reproduced here so you can check the arithmetic.
| Value | 1 |
|---|---|
| From | Bar (bar) |
| To | Pound per square inch (psi) |
| Result | 14.50377377 psi |
|---|---|
| How it was calculated | 1 bar = 14.50377377 psi, so 1 × 14.50377377 = 14.50377377 psi |
| Reverse conversion | 0.068947573 bar (if you meant 1 psi) |
The bar
1 bar is defined as exactly 100,000 pascals (100 kPa): deliberately a round metric number, chosen to sit close to (but not exactly equal to) standard atmospheric pressure (101,325 Pa), a difference of about 1.3%.
Worth knowing
- Because 1 bar is so close to 1 atmosphere, it’s often used informally as a rough stand-in for "normal" air pressure, even though the two are not technically identical: a distinction that matters for precise scientific work but rarely for everyday use.
- Scuba diving, industrial hydraulics and European tire-pressure specifications commonly use bar, while the millibar (1/1000 bar, numerically identical to the hectopascal) remains the standard unit for weather-map pressure readings worldwide.
- Pressure washers and industrial equipment are frequently rated in bar in most of the world and in psi in the US: 1 bar equals about 14.5 psi, a conversion worth remembering when comparing equipment specifications across those markets.
Definitions: BIPM SI Brochure · NIST reference on units
How to use it
- Enter Value.
- Pick a value for From: the options are Pascal (Pa), Hectopascal (hPa), Kilopascal (kPa), Megapascal (MPa), Bar (bar) or Millibar (mbar).
- Pick a value for To: the options are Pascal (Pa), Hectopascal (hPa), Kilopascal (kPa), Megapascal (MPa), Bar (bar) or Millibar (mbar).
- The result appears as you type. There is no button to press.
- You get Result, How it was calculated and Reverse conversion back.
- Copy Link puts the current inputs in the URL, so bookmarking it brings the same numbers back.
What this tool does not do
- Repeated conversions compound rounding, so convert once from the original value where possible.
- Factors use the internationally agreed definitions; some industries round them differently.
- Assumptions built into the method are stated above, but they are still assumptions.
- It validates ranges, not intent. A value can be accepted and still be the wrong one to use.
Frequently asked questions
3 things: Value, From and To. Every box already holds a working value, letting you treat it as a what-if tool rather than a data-entry form.
With the values loaded when the page opens, result comes out as 14.50377377 psi. The figure is derived from the inputs above, so it updates whenever they do.
No record is kept. We never receive what you type, so there is nothing on our side to retain.
No. There is no account, no usage cap and no trial period. The site is funded by advertising rather than by charging for the tools.
It implements the published definition directly, without shortcuts or approximations.