psi to mbar
Convert psi (pounds per square inch) to mbar (millibars) with this free converter. The conversion uses the fixed factor 1 psi = 68.9476 mbar, so a pressure in psi is simply multiplied by 68.9476 to get millibars. psi is the everyday pressure unit in the United States, while mbar is the standard in meteorology, vacuum technology, and much of Europe.
Result
Formula & Conversion Factor
The conversion uses the fixed factor 1 psi = 68.9476 mbar, so the formula is mbar = psi × 68.9476. To convert in the opposite direction, psi = mbar ÷ 68.9476. Both directions are exact because the factor never changes.
| Direction | Factor | Example |
|---|---|---|
| psi to mbar | multiply by 68.9476 | 10 psi = 689.476 mbar |
| mbar to psi | divide by 68.9476 | 689.476 mbar = 10 psi |
Worked Example
Convert a tyre pressure of 32 psi to millibars:
- Start with the value in psi: 32 psi.
- Apply the factor: 32 × 68.9476 = 2206.3232 mbar.
- Round the result to two decimals: 2206.32 mbar.
A second check with the default value: 10 psi × 68.9476 = 689.476 mbar, which is the number shown in the result box above.
psi to mbar Reference Table
Common psi values converted to millibars with the factor 68.9476:
| psi | mbar |
|---|---|
| 1 | 68.9476 |
| 2 | 137.8952 |
| 5 | 344.738 |
| 10 | 689.476 |
| 25 | 1723.69 |
| 50 | 3447.38 |
| 100 | 6894.76 |
Related Tools
External Resources
Frequently Asked Questions
- How do I convert psi to mbar?
- Multiply the pressure value in psi by 68.9476. For example, 10 psi × 68.9476 = 689.476 mbar. Enter any psi value in the field above and press Calculate to get the converted value in millibars instantly.
- What is the formula for psi to mbar?
- The formula is: mbar = psi × 68.9476. The factor comes from the definitions of the psi (pounds per square inch) and the millibar, which is one thousandth of a bar. Because the factor is fixed, the conversion is a simple multiplication.
- How many millibars are in 1 psi?
- One pound per square inch equals 68.9476 millibars. Going the other way, one millibar equals about 0.0145038 psi. This means a pressure reading in psi is always a much smaller number than the same pressure expressed in mbar.
- How many psi is 1 mbar?
- One millibar equals 0.0145038 psi. For a quick estimate, divide the mbar value by 68.9476, which is the same as multiplying by 0.0145038. For example, 100 mbar works out to about 1.45 psi.
- When are psi and mbar each used?
- psi is common in the United States for tyre pressure, hydraulic systems, and industrial gauges. Millibars are used in meteorology and in much of Europe for barometric pressure, vacuum systems, and low-pressure measurements. Converting between them lets you compare readings from instruments that use different scales.
- Is mbar the same as hPa?
- Yes, one millibar equals one hectopascal exactly, so the two names describe the same pressure unit. Weather reports often use hPa while engineers and vacuum technicians usually say mbar. This calculator converts psi to either name with the same 68.9476 factor.
- How do bar, mbar, and psi relate?
- One bar equals 1000 mbar and about 14.5038 psi, so one mbar is about 0.0145038 psi and one psi is about 68.9476 mbar. The bar and millibar belong to the metric family of pressure units, while psi is an imperial unit still used in the United States.
- How accurate is this psi to mbar conversion?
- The conversion factor 68.9476 is a fixed, internationally consistent value, so the mathematics is exact and only the displayed precision is limited. This calculator shows results to four decimal places in mbar. That is more than enough for tyre, hydraulic, and weather applications.