Millibar to PSI Converter
Convert from Millibar (mbar) to Pounds per Square Inch (PSI)
Understanding Millibar and PSI
The millibar (mbar) is a metric unit of pressure equal to 1/1000 of a bar.
- 1 mbar = 100 pascals (Pa) = 0.1 kPa
- Standard atmospheric pressure is approximately 1013.25 mbar
- Widely used in meteorology worldwide, especially in weather forecasting
PSI (pound-force per square inch) is a unit of pressure in the imperial and US customary systems.
- Commonly used in the United States and the UK
- Standard atmospheric pressure is approximately 14.7 PSI
- Widely used for tire pressure, hydraulic systems, and many industrial applications
Conversion Formula
Millibar to PSI:
PSI = mbar × 0.0145038
To convert from millibars to PSI, multiply the millibar value by approximately 0.0145038.
PSI to Millibar:
mbar = PSI × 68.9476
To convert from PSI to millibars, multiply the PSI value by approximately 68.9476.
Millibar to PSI Conversion Table
| Millibar (mbar) | Pounds per Square Inch (PSI) |
|---|---|
| 900 | 13.05 |
| 950 | 13.78 |
| 1,000 | 14.50 |
| 1,050 | 15.23 |
| 1,100 | 15.95 |
| 1,150 | 16.68 |
| 1,200 | 17.40 |
| 1,250 | 18.13 |
| 1,300 | 18.85 |
| 1,350 | 19.58 |
Historical Context and Applications
Historical Development
The millibar emerged in the early 20th century with the bar unit, introduced in 1909 by Norwegian meteorologist Vilhelm Bjerknes. PSI has been used since the Industrial Revolution for measuring pressure in steam engines and other mechanical systems. These units represent two different measurement traditions: the metric system (millibars) and the imperial system (PSI), which are used in different regions and applications worldwide.
Common Applications
- Millibar: The primary unit for meteorological reports and forecasting. Weather maps typically display pressure in millibars, and meteorologists use millibars when discussing atmospheric pressure. Also used in aviation weather reports.
- PSI: Widely used in the United States for measuring tire pressure, hydraulic systems, plumbing, and industrial applications. Most pressure gauges in the US are calibrated in PSI.
Practical Examples
- Standard atmospheric pressure: 1013.25 mbar (14.7 PSI)
- Typical car tire pressure: 2068-2413 mbar (30-35 PSI)
- Bicycle tire pressure: 4137-6895 mbar (60-100 PSI)
- Strong hurricane: <950 mbar (<13.78 PSI)
- Pressure at 18,000 feet: ~500 mbar (~7.25 PSI)
- Enter your value in the millibar (mbar) field
- The converter instantly displays the equivalent in PSI
- Use the swap button to convert from PSI to millibars instead
- Results are displayed with 6 decimal places for precision
For quick reference without calculations, refer to the conversion table above for common values.