Water Tank Volume Calculator
Inside length × width × height of water space.
Step 1: Units
Step 2
Enter project measurements
Use decimals if needed (e.g. 3.5).
How to use this calculator
Measure to high water level, not overflow rim unless you want total shell volume.
What the math is doing
Volume = length × width × height.
Frequently asked questions
Cylindrical tanks?
Use V = π r² h separately.
Freeboard?
Subtract air gap from height.
Potable liner?
Material compatibility matters.
Overflow?
Size per local storm rules.