This tool helps you determine exactly how high to fill a vertical cylindrical tank to reach a specific volume of liquid. It also calculates the ullage (the empty space remaining at the top).
Enter the Tank Radius: Measure the distance from the center of your tank to the outside edge (in inches) and enter it into the first field.
Enter Total Tank Height: Input the total interior height of your tank in inches.
Enter Target Gallons: Type in the specific number of gallons you intend to add to the tank.
Click "Calculate": The tool will immediately provide two key measurements:
Fill Level: The height in inches from the bottom of the tank up to the liquid surface.
Ullage: The measurement from the top rim of the tank down to the liquid surface.
Accuracy: Ensure your measurements are in decimal inches (e.g., use 12.5 instead of 12 ½).
Capacity Warning: If the gallons entered exceed the physical capacity of the tank based on your dimensions, the calculator will display a warning.
Tank Shape: This calculator is designed specifically for vertical cylinders. If your tank has a conical bottom or is sitting horizontally, the math will vary.