Gas Pipe Sizing Calculator

Size gas piping per IFGC/NFPA 54 fuel gas code

Gas Supply

Appliance Load

Pipe Run

Gas Pipe Sizing Results

Minimum Pipe Size --
CFH Capacity --
Total BTU Load --
Required CFH --
Equivalent Length --
Pressure Drop --
Code Reference: IFGC/NFPA 54 Chapter 4. Always verify with local gas utility requirements.

Common Appliance BTU Ratings

Appliance BTU/hr Range
Furnace40,000 - 200,000
Water Heater (Tank)30,000 - 75,000
Water Heater (Tankless)120,000 - 200,000
Range/Oven35,000 - 75,000
Clothes Dryer20,000 - 35,000
Gas Fireplace20,000 - 60,000
Pool Heater100,000 - 400,000
Outdoor Grill30,000 - 60,000

Heating Values

Natural Gas: ~1,030 BTU/cu ft

Specific gravity: 0.60

Propane (LP): ~2,500 BTU/cu ft

Specific gravity: 1.52

Gas Pipe Capacity - Natural Gas (0.5" WC drop)

Maximum CFH capacity for Schedule 40 steel pipe:

Pipe Size 10 ft 20 ft 30 ft 50 ft 75 ft 100 ft
1/2"17512097735950
3/4"360250200152121103
1"680465375285225195
1-1/4"1,400950770580465400
1-1/2"2,1001,4601,180890710615
2"3,9502,7502,2001,6701,3401,150
Values from IFGC Table 402.4(2). Multiply CFH by 1,030 for BTU capacity.