RV Propane Usage
There is a way to roughly calculate propane usage if you plan to do several days of dry camping at a time. You need to know how much propane is in your RV when it is full. An RV propane tank is full at 80% of its capacity to allow for expansion.
Multiply your propane container capacity using one of these formulas, (gallons
or pounds), to determine container BTU capacity. BTUs per gallon equal 91,502.
BTUs per pound equal 21,548. Divide your container BTU capacity by the total
BTU demand of the appliances you are using. BTU appliance demand can normally
be found on the appliance or in the appliance owner's manual. This will give
you an idea of how long you can expect your LP gas to last. For example, if your RV propane container holds 14 gallons of LP gas when it's full, you multiply 14 X 91,502. The result is 1281028. You divide this figure by the total BTU demand of appliances, let's say 43,800 BTUs which gives us approximately 29 hours of use. But beware; at temperatures below zero degrees your container BTU capacity will be reduced by 50% or more.
This tip contributed by Mark Polk at RV Education 101
Note: Calculations based on US gallons - 1 Imperial gallon = 110,000 BTU