How to Measure LP GAS That is Remaining in Your Cylinder?

Firstly you need to weigh the bottle!

Find the "Tare Weight" of the bottle – this is marked on the top of the bottle as "T.C." or "TARE". Examples are 8.25kg (common for a "9kg" cylinder), 4.98kg (common for a "4kg cylinder)

Find the maximum gas capacity of the bottle. Is your bottle a "9kg" or 4kg". This is the weight of the gas that cylinder can carry at full load.

If you don't know this capacity, you can calculate it….

Find the "W.C." marking on the bottle. (Located next to the "T.C." or "T.W."). This is the "Water Capacity". E.g., for a "9 kg" bottle, the "W.C." is 22.0kg.        
This is the volume of water the bottle can hold.

By law, the gas bottle can only be filled to a certain pressure. The normal propane or propane/butane mix at the specified pressure will weigh approximately 41% of the water capacity. E.g. 41% of 22kg = 9kg
Weigh the bottle – a set of bathroom scales is most suitable for this.
E.g., “Your current"9kg"bottle weighs11kg Take off the (TW) “TARE” weight. E.g., 11kg – 8.1kg = 3.9kg. You have 3.9kg of gas remaining from your 9kg capacity or 43%.

If you have any further questions, pop into one of our stores:
Mona Vale
2/91 Darley Street
Ph: (02) 9999 1891

Taren Point
95 Parraweena Road
Ph: (02) 9526 1526

Silverwater HQ
138 Silverwater Road
Ph: (02) 9748 8368