Pressure
inH₂Otopsi
Convert inches of water column (4 °C) (inH₂O) to pounds-force per square inch (psi).
Factor1 inH₂O = 0.03612729 psi
Converter
inH₂O
Accepts numbers or expressions, e.g. 150 + 14.7
Result
psi
Rendered to 6 significant figures.
Formula
Formula
psi = inH₂O × 0.03612729
Multiply any value in inches of water column (4 °C) by 0.03612729 to obtain the value in pounds-force per square inch.
Worked example
Convert 100 inH₂O to psi.
- 01Start with 100 inH₂O.
- 02Multiply by the conversion factor: 100 × 0.03612729 = 3.61273 psi.
Result100 inH₂O = 3.61273 psi
Conversion table
| inH₂O | psi |
|---|---|
| 1 | 0.036127 |
| 2 | 0.072255 |
| 5 | 0.18064 |
| 10 | 0.36127 |
| 20 | 0.72255 |
| 50 | 1.8064 |
| 100 | 3.6127 |
| 200 | 7.2255 |
| 500 | 18.064 |
| 1000 | 36.127 |
Reference values rounded to 5 significant figures for display.
FAQ
What is the conversion factor from inH₂O to psi?
1 inH₂O equals 0.03612729 psi. To convert, multiply the value in inches of water column (4 °C) by 0.03612729.
How do I convert 1 inH₂O to psi?
1 inH₂O = 0.0361273 psi. For any value, multiply by 0.03612729.
How do I convert psi back to inH₂O?
Divide by the same factor — or equivalently, multiply by 27.6799. So 1 psi = 27.6799 inH₂O.
When would I need to convert inch of water column (4 °C) to pound-force per square inch?
Pressure conversions between inH₂O and psi 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).