PSI to Millibar
Convert psi to millibar instantly. 1 psi = 68.9475729317 mbar. Includes the exact factor, a conversion table of common values and the definition of both units.
How to convert psi to millibar
To convert psi to millibar, multiply by 68.9475729317. The relationship is fixed, so the same factor works for any quantity — there is nothing to look up and nothing that changes with temperature, location or context.
mbar = psi × 68.9475729317
PSI to Millibar conversion table
The values people look up most often, rounded for reading. Use the calculator above for anything in between.
| PSI | Millibar |
|---|---|
| 1 psi | 68.947573 mbar |
| 2 psi | 137.895146 mbar |
| 3 psi | 206.842719 mbar |
| 5 psi | 344.737865 mbar |
| 10 psi | 689.475729 mbar |
| 20 psi | 1,378.95 mbar |
| 25 psi | 1,723.69 mbar |
| 50 psi | 3,447.38 mbar |
| 100 psi | 6,894.76 mbar |
| 500 psi | 34,473.79 mbar |
| 1,000 psi | 68,947.57 mbar |
What is a psi?
Pounds per square inch, the US pressure unit for tyres and plumbing.
What is a millibar?
A thousandth of a bar, the meteorologist's unit for air pressure.
The formula
mbar = psi × 68.9475729317
Every result on this page comes from this formula. Nothing is rounded until the final display, so figures match a spreadsheet to the cent.
How to use the PSI to Millibar
- Type the number of psi you want to convert.
- Read the result in millibar straight away — there is no button to press.
- Check the table below for the values that come up most often, or reverse the conversion with the linked millibar to psi page.
PSI to Millibar — frequently asked questions
How many millibar are in a psi?
One psi equals 68.9475729317 mbar. mbar = psi × 68.9475729317
What is the formula to convert psi to millibar?
The formula is mbar = psi × 68.9475729317. It is an exact definition rather than an approximation, so the conversion never drifts no matter how large the number.
How do I convert millibar back to psi?
Divide instead of multiplying: one millibar is 0.0145037738 psi. The reverse converter is linked in the related tools list.
Is this conversion exact?
Yes. Both units are defined against the same base unit by international agreement, so the factor is exact — any rounding you see is only in the display, which you can widen by entering more decimal places.
Is this psi to millibar free to use?
Yes. Every calculator on the site is free, needs no sign-up, and runs entirely in your browser, so your figures never leave your device.
What people search for
This page answers each of these searches. They are the exact phrases visitors use to find the psi to millibar.
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About this calculator
Written and reviewed by The Samsung Calculator editorial team. Every calculator is written against a published formula, reviewed against at least one independent reference implementation, and dated when it changes.
Last reviewed August 19, 2026 · Calculation runs client-side · No data collected · Report an error