Pressure
inHgtoinH₂O
Convert inches of mercury (0 °C) (inHg) to inches of water column (4 °C) (inH₂O).
Factor1 inHg = 13.5951 inH₂O
Converter
inHg
Accepts numbers or expressions, e.g. 150 + 14.7
Result
inH₂O
Rendered to 6 significant figures.
Formula
Formula
inH₂O = inHg × 13.5951
Multiply any value in inches of mercury (0 °C) by 13.5951 to obtain the value in inches of water column (4 °C).
Worked example
Convert 30 inHg to inH₂O.
- 01Start with 30 inHg.
- 02Multiply by the conversion factor: 30 × 13.5951 = 407.853 inH₂O.
Result30 inHg = 407.853 inH₂O
Conversion table
| inHg | inH₂O |
|---|---|
| 1 | 13.595 |
| 2 | 27.19 |
| 5 | 67.976 |
| 10 | 135.95 |
| 20 | 271.9 |
| 50 | 679.76 |
| 100 | 1359.5 |
| 200 | 2719 |
| 500 | 6797.6 |
| 1000 | 13595 |
Reference values rounded to 5 significant figures for display.
FAQ
What is the conversion factor from inHg to inH₂O?
1 inHg equals 13.5951 inH₂O. To convert, multiply the value in inches of mercury (0 °C) by 13.5951.
How do I convert 1 inHg to inH₂O?
1 inHg = 13.5951 inH₂O. For any value, multiply by 13.5951.
How do I convert inH₂O back to inHg?
Divide by the same factor — or equivalently, multiply by 0.07355591. So 1 inH₂O = 0.0735559 inHg.
When would I need to convert inch of mercury (0 °C) to inch of water column (4 °C)?
Pressure conversions between inHg 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).