Online Tool Store
Aquarium Volume Calculator
Aquarium Volume Calculator gives the number to dose against; the figure on the tank is the empty box. Runs entirely in your browser with no upload and no.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
Calculations
Aquarium Volume Calculator
Frontend preview — no upload or external service.
Tank Volume
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How the Aquarium Volume Calculator works
- Measure the internal dimensions rather than using the tank's rated size.
- Subtract substrate depth and estimate hardscape displacement, which together often remove a fifth of the volume.
- Use the real figure for dosing and stocking. Dosing to the rated volume is a consistent overdose.
The method
Rated tank size is the geometric volume of the box, before anything is put in it.
water volume = (L x W x (H - freeboard)) - substrate volume - hardscape displacement
Substrate, rock and the few centimetres below the rim commonly account for 15 to 25% of the rated figure.
FAQ
Why is my real volume so much lower?
Substrate, hardscape and the gap below the rim. A tank filled to its geometric volume would be filled to the brim with bare glass, which nobody runs.
Does this matter for dosing?
Considerably. Fertiliser, medication and water conditioner are dosed per volume, and dosing 270 litres of product into 215 litres of water is a 25% overdose every time.
How do I measure hardscape displacement?
Weigh the rock and divide by its density, or measure the water level rise when it is added. Most aquarium rock displaces roughly its own weight in litres, which is close enough for dosing.
How we compare
| Feature | Online Tool Store | A search-engine answer box | A reference table |
|---|---|---|---|
| Accounts for substrate | ✓ | ✗ | Sometimes |
| Hardscape displacement | ✓ | ✗ | ✗ |
| No sign-up | ✓ | ✓ | ✗ |
| Nothing uploaded | ✓ | ✓ | ✗ |
Aquarium Volume Calculator gives the number to dose against; the figure on the tank is the empty box.