# How do you know how much isobutane is in a full canister (i.e., how much if fuel wht and not cannister)? [duplicate]

If a isobutane canister says 4 oz, does that mean it has 4oz of fuel or is that fuel+canister weight?

And I assume that is 4oz of wheight, not volume, right?

• If you weigh it on some scales you should find that it weighs quite a bit more than 4oz. The difference is the weight of the metal as can be checked by weighing an empty canister. In metric units, gas is sold by weight. Presumably it's the same for imperial units. – Chris H May 15 '16 at 18:20
• It really should say fluid ounces if relating to volume. – Quinto May 17 '16 at 16:13

Isobutate/Propane fuel amounts are usually presented in terms of net weight.

• The small canisters are usually 3.5oz ~ 4oz (100g ~ 110g).
• The medium canisters are usually 7.75oz ~ 8oz (220g ~ 230g).
• The large canisters are usually around the 16oz range (~450g).

The amount of fuel depends on the brand, but that's a general guideline. Most of the "big name brands" will list both the net weight of the fuel and the gross weight of the canister and the fuel.