Fifteen inches of heating oil in a tank with a capacity of 275 gallons is approximately 156 gallons in a horizontal tank. In a vertical tank of the same capacity, 15 inches equates to approximately 86 gallons of heating oil.
The quantity of heating oil at a height of 15 inches in a 275-gallon tank is an approximate figure since the precise size of the tank varies between different manufacturers. Generally, a 275-gallon horizontal tank measures 27 inches in width and 44 inches in diameter. A 275-gallon vertical tank measures 44 inches in width and 27 inches in diameter. Both horizontal and vertical 275-gallon tanks measure 60 inches in length.
Check the height of heating oil in a tank by placing a stick straight into the tank so that its bottom touches the bottom of the tank. Remove the stick, measure the length until the oil mark on the stick and compare it to the heating oil tank chart.
In a 275-gallon horizontal tank, heating oil can reach a height up to approximately 27 inches, at which point the tank is at full capacity. In a 275-gallon vertical tank, the oil height reaches up to approximately 42 inches when the tank is full.