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Pressure

psitoinH₂O

Convert pounds-force per square inch (psi) to inches of water column (4 °C) (inH₂O).

Factor1 psi = 27.6799 inH₂O

Converter

psi

Accepts numbers or expressions, e.g. 150 + 14.7

Result
27.6799inH₂O

Rendered to 6 significant figures.

Formula

Formula
inH₂O = psi × 27.6799

Multiply any value in pounds-force per square inch by 27.6799 to obtain the value in inches of water column (4 °C).

Worked example

Convert 1 psi to inH₂O.

  1. 01Start with 1 psi.
  2. 02Multiply by the conversion factor: 1 × 27.6799 = 27.6799 inH₂O.
Result1 psi = 27.6799 inH₂O

Conversion table

psiinH₂O
127.68
255.36
5138.4
10276.8
20553.6
501384
1002768
2005536
50013840
100027680

Reference values rounded to 5 significant figures for display.

FAQ

What is the conversion factor from psi to inH₂O?
1 psi equals 27.6799 inH₂O. To convert, multiply the value in pounds-force per square inch by 27.6799.
How do I convert 1 psi to inH₂O?
1 psi = 27.6799 inH₂O. For any value, multiply by 27.6799.
How do I convert inH₂O back to psi?
Divide by the same factor — or equivalently, multiply by 0.03612729. So 1 inH₂O = 0.0361273 psi.
When would I need to convert pound-force per square inch to inch of water column (4 °C)?
Pressure conversions between psi 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).

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