Horizontal cylindrical tank fluid volume

If you have an horizontal cylindrical tank and you need to calculate the volume of liquid in the tank then this formula might be helpful. I use this formula to calculate the volume of diesel fuel and oil inside horizontal cylindrical tank.

The formula is only accurate if:
· perfectly cylindrical tank, not oval.
· the ends of the tank are flat, not curved (convex or concave, eliptical).
· tank is at a level position.
· use the measurements on the inside of the tank, especially if the tank skin material is very thick.
· depth gauges of the fluid must be correctly upright or vertical.

Horizontal cylindrical tank that is quite popular with a few advantages over vertical tanks, including:
· easy to built
· transportable by truck
· easy installation at job site
· not too high so easily lifted by the crane
· not susceptible to lightning strikes
· easy to climb for maintenance and check.


The formula used to calculate the volume inside the tank is using Pythagoras and Trigonometry formulas to determine the areas of the ends of the tank that are submerged in the liquid in the tank. Wet end area of tank end is multiplied by the length of the tank will equal to volume of liquid inside the tank.

This Excel workbook includes formula and table of percentage of maximum liquid depth in 5% increments, to compare to percentage of fluid volume. In the graph shows that the percentage of the volume is not linear as the percentage of depth. This needs to be considered if you have to determine the minimal and maximal value of stock.