Aquarium Volume Calculator
Calculate the water volume and recommended fish capacity for a rectangular aquarium based on its dimensions and glass thickness.
Published by:
isCalculator Editorial Team
Was this calculator helpful?
How to use this tool?
Follow these steps to calculate your aquarium’s water volume and recommended fish capacity:
- Enter dimensions in centimeters – Length, Width, and Height. All values must be positive numbers.
- Enter glass thickness in millimeters – This accounts for the space taken by the glass walls. Use 0 if unknown.
- Click “Calculate” – The tool checks your inputs and shows errors if any are invalid.
- Read the results:
- Water Volume – displayed in liters (L), calculated as internal volume after subtracting glass thickness.
- Recommended Fish – total fish length in centimeters, based on the rule: 1 cm of fish per liter of water.
- If inner dimensions become zero or negative (e.g., glass too thick), you’ll see an “Invalid dimensions” message – adjust your inputs.
Note: All measurements must be in metric (cm and mm). The formula automatically converts glass thickness from mm to cm.
Previous Results
| Result | Inputs | Date |
|---|
Frequently Asked Questions
Volume is calculated by subtracting glass thickness from each dimension: inner length = length - 2*thickness, inner width = width - 2*thickness, inner height = height - thickness. Then multiply inner dimensions and divide by 1000 to get liters.
The general rule is 1 cm of fish per liter of water. This is a conservative estimate and may vary by species.
This calculator uses cm. Convert inches to cm (1 inch = 2.54 cm) before entering.