Pressure

PSI to Inches of Water

Convert psi to inches of water instantly. 1 psi = 27.6799058214 inH2O. Includes the exact factor, a conversion table of common values and the definition of both units.

psi
Inches of Water
One step, one exact factorPSIwhat you have× 27.6799058214Inches of Waterwhat you getBoth units are defined against the same base unit, so the factor is exact — never an approximation.

How to convert psi to inches of water

To convert psi to inches of water, multiply by 27.6799058214. The relationship is fixed, so the same factor works for any quantity — there is nothing to look up and nothing that changes with temperature, location or context.

inH2O = psi × 27.6799058214

PSI to Inches of Water conversion table

The values people look up most often, rounded for reading. Use the calculator above for anything in between.

PSIInches of Water
1 psi27.679906 inH2O
2 psi55.359812 inH2O
3 psi83.039717 inH2O
5 psi138.399529 inH2O
10 psi276.799058 inH2O
20 psi553.598116 inH2O
25 psi691.997646 inH2O
50 psi1,384 inH2O
100 psi2,767.99 inH2O
500 psi13,839.95 inH2O
1,000 psi27,679.91 inH2O

What is a psi?

Pounds per square inch, the US pressure unit for tyres and plumbing.

What is a inches of water?

A low-pressure unit used for ventilation and gas appliances.

The formula

inH2O = psi × 27.6799058214

Every result on this page comes from this formula. Nothing is rounded until the final display, so figures match a spreadsheet to the cent.

How to use the PSI to Inches of Water

  1. Type the number of psi you want to convert.
  2. Read the result in inches of water straight away — there is no button to press.
  3. Check the table below for the values that come up most often, or reverse the conversion with the linked inches of water to psi page.

PSI to Inches of Water — frequently asked questions

How many inches of water are in a psi?

One psi equals 27.6799058214 inH2O. inH2O = psi × 27.6799058214

What is the formula to convert psi to inches of water?

The formula is inH2O = psi × 27.6799058214. It is an exact definition rather than an approximation, so the conversion never drifts no matter how large the number.

How do I convert inches of water back to psi?

Divide instead of multiplying: one inches of water is 0.0361272905 psi. The reverse converter is linked in the related tools list.

Is this conversion exact?

Yes. Both units are defined against the same base unit by international agreement, so the factor is exact — any rounding you see is only in the display, which you can widen by entering more decimal places.

Is this psi to inches of water free to use?

Yes. Every calculator on the site is free, needs no sign-up, and runs entirely in your browser, so your figures never leave your device.

What people search for

This page answers each of these searches. They are the exact phrases visitors use to find the psi to inches of water.

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About this calculator

Written and reviewed by The Samsung Calculator editorial team. Every calculator is written against a published formula, reviewed against at least one independent reference implementation, and dated when it changes.

Last reviewed August 19, 2026 · Calculation runs client-side · No data collected · Report an error