Aquarium Volume Calculator
Estimate rectangular aquarium capacity in liters and US gallons. Use inside tank dimensions and actual water depth. A displacement allowance provides a rough adjustment for substrate and décor, but measured fill volume is more reliable for exact dosing.
Use the tool
Enter your values, then run it. The result is generated in your browser.
Result
Calculated
How to use Aquarium Volume Calculator
- Measure the internal glass dimensions.
- Use actual water depth below the waterline.
- Use measured fill volume when precise treatment or stocking calculations matter.
Formula and assumptions
For a rectangular tank: liters = length × width × water depth in centimeters ÷ 1,000; US gallons = liters ÷ 3.785411784.
Tank volume alone does not determine stocking or safe treatment. Follow species-specific care and product instructions.
Frequently asked questions
Why use inside dimensions?
Glass thickness reduces internal capacity compared with exterior dimensions.
Is displacement exact?
No. Substrate and rock shape vary; measuring water added is better.
Can I use it for medication?
Use actual water volume and the product label, not the rough estimate.
About this tool
Use inside tank dimensions and actual water depth. A displacement allowance provides a rough adjustment for substrate and décor, but measured fill volume is more reliable for exact dosing.
No account is required. The tool runs in this browser and this starter build has no form-submission backend. See the method and assumptions before relying on estimates.