Free · Pressure converters

PSI to Conventional Inches of Water Column

Convert pressure to conventional inches of water column using an explicit density, gravity and inch definition.

  • Formula & worked example
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Calculator inputs

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How to use this calculator

  1. Enter the known values in the units shown. Results update as you type.
  2. Where results are editable, change one to solve backwards. Lock a value to hold it fixed.
  3. Use the worked example to check the method. Reset restores the starting fields.

Private by default

Inputs and results stay in this browser tab. Bookify does not upload or store the values you enter.

Formula and method

A pressure of 249.08891 Pa equals one conventional inch of water column. The conversion uses 1,000 kg/m³ water density and standard gravity.

1 inH₂O (conventional) = 1000 × 9.80665 × 0.0254 Pa = 249.08891 Pa

Worked example

Enter these known values and leave the other values blank.

Pressure, initially psi
1 psi
Equivalent conventional water-column pressure
27.6799 inH₂O (conv.)

Assumptions and limitations

  • The inch-of-water option is a conventional pressure unit defined using 1,000 kg/m³ and standard gravity. It does not measure the local water density or gravitational field.
  • Temperature-specific water-column units can have different factors. Check an instrument’s definition before comparing readings.
  • Signed pressure differences are supported. Keep the same pressure reference on both sides; the conversion does not add atmospheric pressure.

Common questions

Is an inch of water a length or a pressure?

Here it is a pressure unit: the hydrostatic pressure associated with a specified conventional one-inch water column.

Do I need to enter water temperature?

No for this conventional unit. For an actual column at a particular temperature and location, calculate density times local gravity times height instead.

References

Bookify uses conventional inches of water based on 1000 kg/m³, standard gravity and the exact international inch instead of the captured approximate factor. Mercury pressure columns use conventional density and standard gravity, with the exact international inch. Pounds-force per square inch use the exact international pound and inch with standard gravity, replacing the rounded captured factor. One technical atmosphere is exactly one kilogram-force per square centimeter under standard gravity. Pounds-force per square foot use the exact international pound and foot with standard gravity. The tonnes-force pressure option uses metric tonnes and standard gravity, with one tonne-force per square meter equal to 9806.65 pascals.

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