Aquarium Volume in Litres

Outside the United States, aquarium dimensions are measured in centimetres and volume is expressed in litres. Fishkeepers in the United Kingdom, Australia, Canada, Germany, France, the Netherlands, Spain, Italy, Brazil, India, South Africa, Japan, and most of Asia and continental Europe all work in metric units — and the tank sizes sold in these markets do not follow the same proportions as US standard sizes. The formula is straightforward — length × width × height (all in centimetres) divided by 1,000 gives litres — but a “60 cm tank” in Germany and a “24-inch tank” in the US are not the same size, and litre-based filter ratings, heater recommendations, and dosing instructions cannot be directly swapped with US-gallon equivalents without conversion. This page provides the metric formula, common international tank sizes with calculated volumes, and quick conversions to US gallons.

The Metric Volume Formula

Volume (litres) = (L × W × H) ÷ 1,000

where L, W, H are all in centimetres.

Example: A 60 × 30 × 36 cm tank

60 × 30 × 36 = 64,800 cm³ ÷ 1,000 = 64.8 litres (≈ 17.1 US gallons)

1 litre
= 0.2642 US gallons
1 US gallon
= 3.7854 litres
1 cm³
= 0.001 litres
1 inch
= 2.54 cm
1 US gallon
= 231 in³

Used by fishkeepers in: Australia · United Kingdom · Germany · France · Netherlands · Belgium · Spain · Italy · Portugal · Brazil · Argentina · Canada · India · Japan · South Korea · South Africa · New Zealand · Singapore · Malaysia · Thailand · and most countries outside the US.

Need more conversions? Use the full aquarium volume unit converter.

Common Aquarium Sizes in Centimetres and Litres

These are commonly sold European and international tank dimensions. US standard sizes use different proportions — see the aquarium volume by size table for US inch/gallon reference data. For manufacturer-labelled volumes across specific tank brands, see aquarium volume by brand.

Size Label L × W × H (cm) Calc. Volume (L) Actual Water (L) US Gallons (approx.) Typical Use
9 L Nano 30 × 15 × 20 9.0 7.8 2.1 Pico / shrimp
16 L Nano 40 × 20 × 25 20.0 17.4 4.6 Nano / betta
30 L Small 50 × 25 × 30 37.5 32.6 8.6 Community nano
54 L 2ft 60 × 30 × 30 54.0 47.0 12.4 Starter community
64 L 2ft 60 × 30 × 36 64.8 56.4 14.9 Starter community
75 L 2ft 60 × 30 × 45 81.0 70.5 18.6 Small community
90 L 60 × 40 × 45 108.0 94.0 24.8 Community
112 L 80 × 35 × 40 112.0 97.4 25.7 Community
125 L Cube 50 × 50 × 50 125.0 108.8 28.7 Cube / reef
160 L 80 × 40 × 50 160.0 139.2 36.8 Medium community
200 L 100 × 40 × 50 200.0 174.0 46.0 Large community
200 L Cube 60 × 45 × 75 202.5 176.2 46.6 Tall display
240 L 3ft 90 × 45 × 60 243.0 211.4 55.9 Large community
250 L 100 × 50 × 50 250.0 217.5 57.5 Large community
300 L 100 × 50 × 60 300.0 261.0 69.0 Large community
300 L 4ft 120 × 50 × 50 300.0 261.0 69.0 Large display
360 L 4ft 120 × 50 × 60 360.0 313.2 82.7 Large display
454 L 4ft 120 × 60 × 60 432.0 375.8 99.3 XL / reef
540 L 5ft 150 × 60 × 60 540.0 469.8 124.1 XL display
Calc. Volume uses exact formula (L × W × H ÷ 1,000). Actual Water applies a 0.87 factor for glass thickness, a 2 cm fill gap, and minor displacement. Measure inside glass for precise results.

Metric Volume Formulas by Shape

Rectangular / Cube / Breeder / Shallow
V (L) = (L × W × H) ÷ 1,000
Cylinder
V (L) = (π × r² × H) ÷ 1,000
r = interior radius in cm, H in cm
Hexagon
V (L) = (3√3 ÷ 2) × s² × H ÷ 1,000
s = side length in cm
Bow Front
V (L) = (L × D × H + π × (L÷2) × B × H ÷ 2) ÷ 1,000
D = flat depth, B = bow depth, all in cm
Fish Bowl
V (L) = (4÷3 × π × r³) ÷ 1,000
r = interior radius in cm

For all 20 shapes with full worked examples, see the aquarium volume formulas page.

Metric vs US Aquarium Sizing

European and international aquariums — sold in the UK, Australia, Germany, France, the Netherlands, Spain, Italy, Brazil, India, Japan, and most countries outside the United States — use metric dimensions and litre ratings that do not map neatly onto US gallon sizes. A standard “60 cm tank” (60 × 30 × 36 cm) holds about 64.8 litres — roughly 17 US gallons — which falls between the US 15-gallon and 20-gallon High standard sizes. This means metric-market filter ratings, heater watt recommendations, and stocking guides quoted in litres cannot be directly substituted with US-gallon guidance without conversion. Use the unit converter to translate between systems accurately.

The 0.87 actual-water factor used in the table above is a conservative estimate. On a 60 × 30 × 36 cm tank with 6 mm glass walls, the interior length is 58.8 cm, width 28.8 cm — reducing calculated volume from 64.8 L to about 60.9 L brimful. With a 2 cm air gap at the top and a light substrate, usable water is closer to 56–58 L. For dosing, always measure inside the glass and use the interior dimensions in the formula. For measurement techniques, see how to measure aquarium volume, or use the displacement calculator to account for substrate and hardscape.

Aquarium Volume in Litres — Questions

How do I calculate aquarium volume in litres?
Measure the interior length, width, and height of your tank in centimetres. Multiply all three together to get cubic centimetres, then divide by 1,000 to convert to litres. For example, a tank measuring 60 × 30 × 36 cm has a volume of 60 × 30 × 36 = 64,800 cm³ ÷ 1,000 = 64.8 litres. For a filled-tank estimate, subtract about 10–15% to account for glass thickness, substrate, and fill height.
How many litres is a standard 60 cm fish tank?
It depends on the depth and height. A common 60 × 30 × 30 cm tank holds 54 litres calculated, with roughly 47 litres of usable water. A taller 60 × 30 × 36 cm holds about 64.8 L calculated (56–58 L usable). A deeper 60 × 40 × 40 cm holds about 96 L calculated. Always check the actual dimensions of your specific tank rather than relying on the length alone.
How do I convert aquarium litres to US gallons?
Multiply litres by 0.2642 to get US gallons, or divide by 3.7854. For example, 200 litres × 0.2642 = 52.8 US gallons. For quick mental maths, divide litres by 4 for a rough US gallon estimate (200 ÷ 4 = 50 gallons). Use the aquarium volume unit converter for precise results across all units.
What is the volume of a 100 cm aquarium?
“100 cm” refers to the length only. The volume depends on all three dimensions. A common 100 × 40 × 50 cm tank calculates to 200 litres (about 53 US gallons). A deeper 100 × 50 × 50 cm tank calculates to 250 litres (about 66 US gallons). Measure or check all three dimensions for an accurate result.
Why does my tank hold less water than the litre rating on the box?
Manufacturer litre ratings are calculated from exterior dimensions and rounded. Interior dimensions are smaller due to glass thickness — typically 6–10 mm per panel on mid-size tanks. With substrate and a fill gap of 2–3 cm below the rim, usable water is usually 85–90% of the stated litre rating. A “200 litre” tank realistically holds 170–180 litres of water once set up.
Do metric and US tanks have the same dimensions?
No. European and international tank sizes follow metric conventions — 60 cm, 80 cm, 90 cm, 120 cm lengths are most common — while US standard tanks are based on imperial dimensions (typically 16″, 20″, 24″, 30″, 36″, 48″, 72″ lengths). A 60 cm European tank is not exactly the same size as a 24-inch US tank: 60 cm = 23.62 inches, so a “60 cm” tank is slightly narrower. The volume difference is small but relevant for filter sizing and equipment compatibility.
Which countries use litres for aquarium volume?
Almost every country outside the United States measures aquarium volume in litres and dimensions in centimetres. This includes the United Kingdom, Australia, New Zealand, Canada, Germany, France, the Netherlands, Belgium, Switzerland, Austria, Spain, Portugal, Italy, Brazil, Argentina, India, Japan, South Korea, China, South Africa, Singapore, Malaysia, Thailand, and all other countries that use the metric system. The United States is the primary market where gallons and inches remain the standard for aquarium sizing.

Related Tools and References

To calculate aquarium volume in litres from your own centimetre measurements, use the free aquarium volume calculator.