1 pound per square inch [psi] = 27.679905 inch of water [inH2O]
Example: 1 pound per square inch [psi] equals 27.679905 inch of water [inH2O].
Examples
1 pound per square inch [psi] = 27.679905 inch of water [inH2O]
2 pound per square inch [psi] = 55.359809 inch of water [inH2O]
5 pound per square inch [psi] = 138.399524 inch of water [inH2O]
10 pound per square inch [psi] = 276.799047 inch of water [inH2O]
20 pound per square inch [psi] = 553.598094 inch of water [inH2O]
25 pound per square inch [psi] = 691.997618 inch of water [inH2O]
Practical Uses for psi to inch water
tire inflationcompressors and pumpsHVAC and plumbingengineering specifications
Sources and Accuracy
Pressure conversions use pascal as the reference unit and include common engineering, weather, tire, and laboratory pressure units.
Displayed results are rounded for readability. The calculator keeps enough precision for everyday use and switches to scientific notation for very large or very small values. Last reviewed: 2026-08-14.
About These Units
pound per square inch [psi]
Definition
Pound per square inch is a pressure unit showing pounds-force applied over one square inch.
History
PSI comes from imperial force and area units and remains common in mechanical and pressure-gauge contexts.
Current use
PSI is used for tire pressure, compressors, plumbing, hydraulics, gas cylinders, and equipment ratings.
inch of water [inH2O]
Definition
The inch of water (inH2O) is a pressure unit used to express measurements in this converter.
History
This unit is included because it appears in practical measurement systems, technical references, product specifications, or everyday conversion needs.
Current use
Use inch of water when comparing pressure values, checking specifications, converting between systems, or preparing quick estimates.
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How to Convert
Enter the value in the “From value” field.
Confirm the source unit is pound per square inch [psi].
Confirm the target unit is inch of water [inH2O].
Read the instant result and formula.
Where This Conversion Is Used
tire inflationcompressors and pumpsHVAC and plumbingengineering specifications