Gas Pipe Sizing - NFPA 54

Gas Pipe Sizing Calculator helps you size natural gas and propane piping systems per NFPA 54 (National Fuel Gas Code). Instantly determine correct pipe diameter for black iron, CSST (corrugated stainless steel tubing), and copper Type L piping based on BTU demand, inlet pressure, and pipe run length. Works for low-pressure, 2-psi, and 5-psi systems. Perfect for plumbers, gas fitters, and HVAC technicians. Works 100% offline on the job site.

FEATURES
• Dual Gas Support: Natural gas and propane (LP) with automatic BTU conversion (propane x 2.52 multiplier)
• 3 Pipe Materials: Black iron, CSST (corrugated stainless steel tubing), and copper Type L with material-specific sizing tables
• 3 Inlet Pressure Classes: Low pressure (<2 psi), 2 psi, and 5 psi system support
• 9 Pipe Diameters: Sizing from 1/2 inch through 2 inches with exact NFPA 54 capacity tables
• 10 Length Brackets: Support pipe runs from 10 feet to 100+ feet
• BTU Input Options: Enter appliance BTU demand or total system demand in BTU/h
• Propane Conversion: Automatic handling of propane vs. natural gas pressure loss differences

HOW IT WORKS
1. Select gas type (natural gas or propane)
2. Enter inlet pressure (low pressure, 2 psi, or 5 psi)
3. Input total BTU demand from gas appliances
4. Enter pipe material (black iron, CSST, or copper Type L)
5. Enter longest pipe run distance
6. See recommended pipe diameter with NFPA 54 capacity verification

PERFECT FOR
• Plumbers installing natural gas and propane systems
• Gas fitters and propane technicians
• HVAC technicians sizing gas furnace piping
• Plumbing contractors and estimators
• Mechanical engineers designing gas systems
• Plumbing inspectors verifying system compliance

OPTIONAL PRO UPGRADE — $2.99 ONE-TIME IN-APP PURCHASE
The following features require a separate one-time in-app purchase. They are not required to use the calculator:
• Unlimited saved calculation history
• PDF export of results
• Dark theme
• Ad-free experience

STANDARDS & COMPLIANCE
NFPA 54 (National Fuel Gas Code) - complete gas pipe sizing tables for low pressure, 2 psi, and 5 psi systems with all approved materials. IBC (International Building Code) gas piping requirements. Local code compliance for natural gas and propane installations. Fully compliant with 2024 National Fuel Gas Code standards.

PERFECT FOR
• Plumbers and gas fitters
• HVAC technicians and contractors
• Propane technicians and installers
• Plumbing contractors and estimators
• Mechanical engineers
• Code officials and inspectors

OFFLINE & PRIVACY
• Works 100% offline - no internet needed for calculations
• No account required - instant access without signup
• No data collection - all calculations stored locally
• No tracking or cloud dependencies

Part of PlumbTools Suite - professional plumbing and HVAC calculator tools. Size gas systems faster, eliminate sizing errors, and ensure full NFPA 54 code compliance with accurate gas pipe sizing calculations.