PSI to Millibar Converter
One PSI equals 68.94757293 Millibar (1 psi = 68.94757293 mbar). Multiply a PSI value by 68.94757293 to get the equivalent in Millibar. Use the calculator above for instant results, or follow the formula, worked examples, and reference table below.
Formula
mbar = psi × 68.94757293
Multiply the PSI value by 68.94757293 to get the equivalent value in Millibar.
Example Conversions
1 PSI (psi)
68.94757293 Millibar (mbar)
5 PSI (psi)
344.7378647 Millibar (mbar)
10 PSI (psi)
689.4757293 Millibar (mbar)
25 PSI (psi)
1723.689323 Millibar (mbar)
100 PSI (psi)
6894.757293 Millibar (mbar)
Conversion Table
| PSI (psi) | Millibar (mbar) |
|---|---|
| 0.1 | 6.894757293 |
| 0.5 | 34.47378647 |
| 1 | 68.94757293 |
| 2 | 137.8951459 |
| 5 | 344.7378647 |
| 10 | 689.4757293 |
| 25 | 1723.689323 |
| 50 | 3447.378647 |
| 100 | 6894.757293 |
| 250 | 17236.89323 |
| 500 | 34473.78647 |
| 1000 | 68947.57293 |
How to Convert Manually
Use these steps to convert PSI values to Millibar without the calculator.
- Write down the value in PSI (psi) that you want to convert.
- Multiply that value by 68.94757293.
- For example, 10 PSI × 68.94757293 = 689.4757293 Millibar.
- Label the result as Millibar (mbar).
Relative Size Comparison
This chart shows the visual difference in size between exactly one PSI and one Millibar.
About PSI and Millibar
The pound per square inch is about 6,894.757 pascals. US tire pressures, water systems, and industrial equipment are rated in psi. The millibar is one thousandth of a bar, identical to the hectopascal. Meteorology has used millibars for surface pressure maps and storm intensity for a century. One PSI equals 68.94757293 Millibar (1 psi = 68.94757293 mbar). PSI to Millibar conversion comes up most often in US tire pressure and in US plumbing and well systems, typically when figures need restating for weather maps and forecasts.
Precision and Rounding: Several pressure factors are exact by definition (1 atm = 101,325 Pa; 1 bar = 100,000 Pa) while others, like psi and mmHg, are derived and carry long decimals. Tire and weather readings tolerate whole-number rounding; calibration, medicine, and process engineering need the full factor before rounding.
Conversion factors per NIST Special Publication 811 and the BIPM SI Brochure (9th edition) (reference).
Worked Example
15 PSI equals 1034.213594 Millibar.
15 psi × 68.94757293 = 1034.213594 mbar
FAQ
How do I convert PSI to Millibar?
Multiply the PSI value by 68.94757293 to get the equivalent value in Millibar.
What is the formula for PSI to Millibar?
The formula is mbar = psi × 68.94757293.
How many Millibar are in 1 PSI?
1 PSI equals 68.94757293 Millibar.
Can I convert Millibar back to PSI?
Yes. 1 Millibar equals 0.01450377377 PSI, and the related converter can reverse the calculation.
What are common names for PSI and Millibar?
PSI is shown as psi and may also be searched as pounds per square inch, lbf/in². Millibar is shown as mbar and may also be searched as millibars, mb.
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