30. You just said it's a 30 gallon tank.
Mine holds 127 gallons of propane when filled up to the 80% make, the fullest they can get.
It is approx 1,463,776 Imperial gallons.
A 5-pound propane cylinder contains approximately 1.2 gallons of propane. This is based on the fact that propane weighs about 4.24 pounds per gallon. Therefore, to convert the weight to gallons, you divide the weight of the propane by the weight per gallon.
Propane weighs 4.4 lbs per gallon, so 20 lbs of propane 4.54 gallons.
A 60-pound propane tank typically holds about 14 gallons of liquid propane. This is based on the fact that propane weighs approximately 4.24 pounds per gallon. Therefore, when you divide the total weight of the propane in the tank by the weight per gallon, you arrive at roughly 14 gallons.
1 pound of propane is a little less than 1/4 of a gallon.
The weight of a 375-gallon propane tank will vary depending on the level of propane it contains. Propane weighs about 4.2 pounds per gallon. Therefore, a full 375-gallon propane tank would weigh approximately 1,575 pounds.
7.1 gallons @ 4.2lbs per gallon.
According to the Wikipedia entry for propane, liquid propane has thermal energy 91,600 BTU per gallon. So 1 therm which is 100,000 BTU will correspond to 100,000/91,600 gallons, result = 1.092 gallons.
To find out how many gallons are left in the tank at 30%, you can multiply the tank's total capacity by 0.30 (which represents 30%). For a 250 gallon tank, this would be 250 * 0.30 = 75 gallons left at 30%.
On average, one gallon of propane contains about 0.73 gallons of gasoline equivalent. This means that you would need around 1.37 gallons of propane to equate to 1 gallon of gasoline in terms of energy content.
100 pound propane tank will hold 23.58 gallon. 100 pounds / 4.24 pounds per gallon = 23.58 gallons