A) Pipe Volume
Enter only the pipe sizes used. Leave unused fields blank.
Copper
Steel / stainless steel
B) Fittings +10%
A × 1.1
C) Meter Volume
D/E) Gas Type
Disclaimer
This calculator is provided as a guide only and is intended to assist with calculations in line with IGEM/UP/1B Edition 4.
Results are based on the values entered and include a standard 10% allowance for fittings. The accuracy of the output depends on the accuracy of the input data, including estimated pipe lengths and routing.
This tool does not replace professional judgement. Users should always verify results and refer to the full IGEM/UP/1B guidance where required.
TomKat Gas Training accepts no liability for any decisions made based on the use of this calculator.
© TomKat Gas Training. This calculator and its logic are provided for use on this website only. Unauthorised copying, reproduction, or redistribution is not permitted.
FAQs
1. What about hidden pipework?
You don’t measure hidden pipe exactly.
Estimate the route based on the install and allow accordingly.
If in doubt, err on the safe side.
2. Does this include fittings?
Yes — a standard 10% allowance for fittings is automatically applied.
This matches typical on-site calculation methods.
3. How accurate is the result?
The result is only as accurate as the inputs.
Always use professional judgement and refer to IGEM/UP/1B where required.
4. Do I need to include every section of pipe?
Yes — include all pipework between the meter and appliance as best as you can determine.
For hidden sections, estimate the likely route.
5. What if my result seems high or low?
Double check your inputs first.
If it still looks off, reassess your estimated pipe route and lengths.
6. Does this replace the IGEM standard?
No — this is a guide to speed up calculations.
You should still refer to the full IGEM/UP/1B Edition 4 guidance where required.