Tank and aquarium volume
Estimate water capacity and water-change volume from internal dimensions and fill height. Drag the graph handles to change inputs and explore the result.
Your inputs
Values shown are editable examples; verify your own measurements and product specifications. Results update as you edit.
Calculations run in your browser. Inputs are not saved or sent to analytics.
How it works
- V_f = × × / 1,000; V_f = π × ( / 2)² × / 1,000
- V = × × / 1,000; V = π × ( / 2)² × / 1,000; Usable water volume = Filled volume before displacement −
- Worked example: 80 × 35 × 35 / 1,000 − 5 = 93 L; 25% ⇒ 23.25 L
Input and formula key
Your result
Complete the inputs to see your result.
Assumptions and limitations
Use internal centimetres for a rectangular tank or a vertical circular cylinder. Fill height must not exceed internal height. Subtract only the entered submerged displacement of solid objects at that fill level; displacement cannot exceed filled volume. The change percentage applies to usable water. Excludes rounded corners, bow fronts, substrate porosity, plumbing, equipment specifications and load-bearing design.
Sources
- OpenStax — volume and geometry Sources reviewed: 2026-10-09
