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.
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