LPG Gas Rate Calculator UK

Propane and butane are both LPG (Liquefied Petroleum Gas) but have different properties. Propane has a lower boiling point (-42°C) making it suitable for outdoor use in cold weather. Butane has a higher boiling point (0°C) and is typically used for indoor portable appliances. Propane also has a slightly lower calorific value (93.2 MJ/m³) compared to butane (121.8 MJ/m³).

LPG has a much higher calorific value than natural gas (39.5 MJ/m³). Propane is approximately 93.2 MJ/m³ and butane approximately 121.8 MJ/m³. This means LPG produces more heat per cubic metre, so appliances use less volume of gas but the heat output can be similar or higher than natural gas equivalents.

Gas rating LPG appliances follows the same principle as natural gas: measure gas consumption over time and calculate the heat input. However, you must use the correct calorific value for the LPG type (propane or butane). This calculator automatically applies the correct CV for your selected gas type.

No - using a standard natural gas calculator will give incorrect results for LPG. Natural gas calculators use a CV of approximately 39.5 MJ/m³, whereas propane is 93.2 MJ/m³ and butane is 121.8 MJ/m³. This would result in significantly underestimating the heat input of an LPG appliance.

LPG installations may use dedicated LPG meters or flow sensors. Many domestic LPG installations (especially cylinder-fed) don't have meters, so gas rating is typically done using the timed test dial method if a meter exists, or by monitoring cylinder weight change over time. Commercial installations usually have dedicated meters.

Yes. Working on LPG requires specific qualifications in addition to standard domestic gas qualifications. Engineers need CCN1/CPA1 core credentials plus specific LPG modules such as LAL1 (LPG Core), CCLP1 (Changeover LPG), and appliance-specific categories. Check the Gas Safe Register for current requirements.