Standards-compliant calculators for gasfitters in NZ & Australia. Free, no signup required. Works on mobile.
Each calculator opens on its own page — bookmark the ones you use most.
Size natural gas and LPG pipes using Spitzglass formula. NZS 5261 / AS/NZS 5601 guidelines.
Convert BTU/hr ↔ kW ↔ MJ/h. Includes gas consumption in m³/h and kg/h.
Total connected gas load with NZS 5261 diversity factors. Recommends meter size.