Guides
How Much Aquarium Substrate Do I Need?
Work out exactly how much gravel, sand or aqua soil your tank needs, the right depth, and how many bags to buy.
Read more →Fish Tank Dimensions Calculator
Volume
—
Enter your tank dimensions to see the volume.
Did we solve your problem?
Turn your tank dimensions into an exact volume. Enter length, width and height and the calculator returns the capacity in litres and gallons.
From dimensions to volume
For a rectangular tank, volume equals length times width times height. Keep all three measurements in the same unit, and the calculator converts the result to litres, gallons and cubic centimetres.
Volume at a glance
Drag to fill a 60 by 30 by 30 cm (54 L) tank and watch the volume change.
50% full = 27 L
Formula
V = length × width × height Related calculators
Frequently asked questions
How do I work out volume from dimensions?
Multiply length by width by height in the same unit, then convert. The tool handles the conversion for you.
Which dimensions do I need?
Length, width and height for a box tank. Cylinders need diameter and height, and corner tanks need the radius.
Do the dimensions need the same unit?
Yes. Mixing units gives a wrong answer, so measure all sides in cm, inches or another single unit.
Can I enter dimensions in inches or feet?
Yes. Choose the unit in the calculator and enter your dimensions in inches, feet, centimetres, millimetres or metres.
What units can I use in this calculator?
You can switch between centimetres, millimetres, inches, feet and metres at any time. Enter all dimensions in the same unit and the result updates instantly.
Does the result include substrate and decoration?
The figure is the full internal capacity. Subtract roughly 10 to 15 percent for substrate, rocks and the gap you leave at the top to estimate the real water volume.
How accurate is this fish tank calculator?
It uses the exact geometric formula for each shape, so the result is accurate for the dimensions you enter. Measure the inside of the tank for the best accuracy.
Is this calculator free to use?
Yes. It is completely free, needs no sign-up, and works on phones, tablets and desktops.
Related guides
Learn the core ideas behind fish tank volume before or after using the calculator.
Care Guides
What Size Tank Does a Betta Fish Need?
Bettas do not belong in bowls. The real minimum tank size for a betta in litres and gallons, plus heater, filter and tank mate advice.
Read more →Equipment Guides
What Size Heater Does My Aquarium Need?
Pick the right aquarium heater wattage for your tank size and room temperature, with a simple watts-per-litre rule and a free heater calculator.
Read more →