Plumbing calculators
Size fuel gas piping from the appliance load and the length of the longest run, using the same equation the code's tables are built from.
Sizing a gas system
- Total the load. Add the input rating from every appliance nameplate, in BTU per hour, and divide by the gas's heating value to get cubic feet per hour.
- Find the longest run. Measure the developed length from the meter or regulator to the farthest appliance.
- Size every section at that length. Under the longest-length method in IFGC 402.4.1, each section uses the longest run's length and is sized for the appliances downstream of it.
Material and pressure change the answer. Schedule 40 steel, CSST, copper and polyethylene each have their own tables, as do propane and 2 psi systems. Gas work needs a permit and a qualified installer in most places.