Home › Pressure converter

Gas Pressure Converter

Convert between PSI, inches of water column and kilopascals. The three units gas work moves between constantly.

Value Unit

The conversions

1 PSI = 27.68" w.c.
1" w.c. = 0.0361 PSI
1 kPa = 4.015" w.c.

Values worth recognising

Pressure	Inches w.c.	PSI
Typical natural gas appliance manifold	3.5" w.c.	0.126
Typical natural gas supply	7" w.c.	0.253
Typical propane appliance manifold	10" w.c.	0.361
Propane supply	11" w.c.	0.397
1 PSI	27.68" w.c.	1.0

The 27.68 figure is the one to memorise. It appears on the G3 exam in both directions, and deriving it under time pressure wastes minutes you will want later.

Studying for the G3 exam?

This is one of the figures the Ontario G3 exam expects you to know without reaching for a calculator. The app has 1,184 practice questions across all 9 syllabus topics, with a free 20-question mock exam.

Try the free mock exam →

Gas properties and conversions →

Tools and measurements on the G3 exam →

Other free tools

Temperature converterCelsius to Fahrenheit and back, with the formulas and the values that come up in gas work.BTU / kW converterConvert between BTU per hour, kilowatts and boiler horsepower — the three ways heating capacity gets quoted.Combustion airHow much air an appliance needs, from its input rating — for natural gas or propane.Pipe sizing helperWork through the four steps with your own numbers.