Calculator
Aquarium volume calculator
Enter the tank dimensions in centimetres. The calculator gives the capacity, the real amount of water and the approximate weight your stand has to carry.
Updated:
How to calculate aquarium volume
litres = length × width × height [cm] ÷ 1000 (1 US gallon = 3.785 l)
That is the capacity of the glass. There is less water: the substrate takes a few centimetres and the water usually ends 2–4 cm below the rim. Dose fertilisers, medication and conditioner for the real amount of water, not the nominal capacity.
Volume calculator
Common aquarium sizes
| Dimensions (cm) | Capacity | Water (approx.) |
|---|---|---|
| 40 × 25 × 25 | 25 l (6.6 gal) | 17 l |
| 60 × 30 × 30 | 54 l (14 gal) | 40 l |
| 60 × 30 × 35 | 63 l (17 gal) | 49 l |
| 80 × 35 × 40 | 112 l (30 gal) | 90 l |
| 100 × 40 × 50 | 200 l (53 gal) | 168 l |
| 120 × 40 × 50 | 240 l (63 gal) | 202 l |
| 150 × 50 × 60 | 450 l (119 gal) | 390 l |
Aquarium weight and the stand
A litre of water weighs about 1 kg and substrate (gravel, sand) about 1.6 kg per litre. Add the glass, rocks and equipment. A 112 l tank with substrate and glass already weighs over 120 kg, so it needs a stand made for aquariums and a level floor. More on choosing a spot: how to set up an aquarium.
What you need the volume for
- choosing heater size and filter flow,
- dosing fertiliser, conditioner and medication,
- planning water changes: 30% of 112 l is about 27 l of real water.
Aquarium Monitor works out water-change litres itself: the level sensor measures how many cm the water dropped and the app converts that using the tank dimensions.
Frequently asked questions
How much water is really in an aquarium?
Usually 75–85% of the nominal capacity. The rest is substrate, decor and the gap below the rim.
How much does a 240 litre aquarium weigh?
The water alone about 200 kg; with substrate, glass and decor usually 260–300 kg.
Keep an eye on your tank from your phone
The app is free and ad-free. The monitor runs on your Raspberry Pi.