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Pressure

ftH₂OtoinH₂O

Convert feet of water column (4 °C) (ftH₂O) to inches of water column (4 °C) (inH₂O).

Factor1 ftH₂O = 12 inH₂O

Converter

ftH₂O

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

Result
120inH₂O

Rendered to 6 significant figures.

Formula

Formula
inH₂O = ftH₂O × 12

Multiply any value in feet of water column (4 °C) by 12 to obtain the value in inches of water column (4 °C).

Worked example

Convert 10 ftH₂O to inH₂O.

  1. 01Start with 10 ftH₂O.
  2. 02Multiply by the conversion factor: 10 × 12 = 120 inH₂O.
Result10 ftH₂O = 120 inH₂O

Conversion table

ftH₂OinH₂O
112
224
560
10120
20240
50600
1001200
2002400
5006000
100012000

Reference values rounded to 5 significant figures for display.

FAQ

What is the conversion factor from ftH₂O to inH₂O?
1 ftH₂O equals 12 inH₂O. To convert, multiply the value in feet of water column (4 °C) by 12.
How do I convert 1 ftH₂O to inH₂O?
1 ftH₂O = 12 inH₂O. For any value, multiply by 12.
How do I convert inH₂O back to ftH₂O?
Divide by the same factor — or equivalently, multiply by 0.08333333. So 1 inH₂O = 0.0833333 ftH₂O.
When would I need to convert foot of water column (4 °C) to inch of water column (4 °C)?
Pressure conversions between ftH₂O 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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