Pressure
mbartoinH₂O
Convert millibars (mbar) to inches of water column (4 °C) (inH₂O).
Factor1 mbar = 0.4014631 inH₂O
Converter
mbar
Accepts numbers or expressions, e.g. 150 + 14.7
Result
inH₂O
Rendered to 6 significant figures.
Formula
Formula
inH₂O = mbar × 0.4014631
Multiply any value in millibars by 0.4014631 to obtain the value in inches of water column (4 °C).
Worked example
Convert 100 mbar to inH₂O.
- 01Start with 100 mbar.
- 02Multiply by the conversion factor: 100 × 0.4014631 = 40.1463 inH₂O.
Result100 mbar = 40.1463 inH₂O
Conversion table
| mbar | inH₂O |
|---|---|
| 1 | 0.40146 |
| 2 | 0.80293 |
| 5 | 2.0073 |
| 10 | 4.0146 |
| 20 | 8.0293 |
| 50 | 20.073 |
| 100 | 40.146 |
| 200 | 80.293 |
| 500 | 200.73 |
| 1000 | 401.46 |
Reference values rounded to 5 significant figures for display.
FAQ
What is the conversion factor from mbar to inH₂O?
1 mbar equals 0.4014631 inH₂O. To convert, multiply the value in millibars by 0.4014631.
How do I convert 1 mbar to inH₂O?
1 mbar = 0.401463 inH₂O. For any value, multiply by 0.4014631.
How do I convert inH₂O back to mbar?
Divide by the same factor — or equivalently, multiply by 2.490889. So 1 inH₂O = 2.49089 mbar.
When would I need to convert millibar to inch of water column (4 °C)?
Pressure conversions between mbar and inH₂O are common when working with mixed-vendor instrumentation, when piping codes use different units to process datasheets, or when converting field readings into SI for hydraulic calculations.
Is the conversion exact?
The factor shown is precise to at least 7 significant figures. For most process-engineering work this is far better than instrument accuracy. For metrology or trade applications, refer to the relevant national standard (NIST, BIPM, ISO 80000).