Free Gasfitter Calculator

Gas Appliance Load Calculator

Add all gas appliances to calculate total connected load, design load with diversity, and required meter size.

Gas Appliances

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Frequently Asked Questions

What is a gas diversity factor?

A diversity factor accounts for the fact that not all gas appliances run simultaneously at full load. NZS 5261 specifies diversity factors: 1.0 for 1 appliance, 0.85 for 2–3 appliances, 0.75 for 4–6 appliances, and 0.65 for 7 or more. The design load is the connected load multiplied by the diversity factor.

How do I calculate total gas load for a house?

Add up the MJ/h input ratings of all gas appliances from their nameplates or manufacturer data sheets. Apply the diversity factor from NZS 5261 to get the design load. This calculator does all of that automatically.

What size gas meter do I need?

Meter sizing depends on the design load. A G2.5 meter handles up to 25 MJ/h (small apartments), G4 up to 65 MJ/h (typical residential), G6/G10 up to 160 MJ/h (large homes). Always confirm with the gas network operator.