Aquarium Calculator

Use this aquarium calculator to measure the volume of the fish tank and determine how much water you need to fill up your aquarium box.

Having an accurate water volume is crucial for various aspects of aquarium management, such as appropriate aquarium stocking levels, water treatment dosages, and overall tank maintenance. It helps in choosing the optimal aquarium size and sizes for powerheads and return pumps.

How To Estimate Aquarium Water Volume?

Aquariums come in various shapes, each requiring specific volume formulas for precise calculation.

See the following tank volume formulas for various fish tank shapes:

Rectangular Prism Shape:

rectangular fish tank

Rectangular = Height * Width * Length

Cubic Shape:

cubic fish tank

Cube = Length^3

Regular Hexagonal Shape:

For a regular hexagon, each side is of the same length. So we have: Volume = ((3*√3)/2) * Front Width² * Height

Flat Back Hexagon Shape:

flat back hexagonal fish tank

Volume = (((((3*√3)/2) * front width²)/2) + (side * length)) * height

Octagonal Shape:

octagonal fish tank

Volume = (2 * (front width²) * (1+√2)) * height

Cylindrical Shape:

cylindrical fish tank

Regular Cylinder:

Cylinder = π * (Diameter / 2)^2 * Height

Half Cylinder:

half cylindrical fish tank

Half_Cylinder = π * (Diameter / 2)^2* Height / 2

Quarter Cylinder:

quarter cylindrical fish tank

Quarter_Cylinder = π * Radius² * Height / 4
We recommend you use the radius of the shape in order to make the computations faster and easier.

Diameter = 2 * Radius

Bow Front Shape:

bow front fish tank

Bowfront = Height * Width * Length + 0.5 * r^2 * (α - sin(α)) * Height Where:

α = Central angle
r = Circle section radius

L Shaped Tank:

L shaped fish tank

Volume = ((Length 1 * Width 1) + ((Length 2 – Width 1) * Width 2)) * Height

Elliptical Shape:

elliptical fish tank

Volume³ = ? * radius 1 * radius 2 * height

Corner Pentagon Shape:

Corner Prism Tank:

corner prism fish tank

Volume = ((Length 1 * Length 2)/2) * Height

Use the above-mentioned formulas to determine your fish tank's volume and verify the results of your calculations with the help of our aquarium Calculator.

Aquarium Weights & Sizes:

SMALL-SIZED AQUARIUMS
Tank Size	L x W x H	Empty Weight	Plants & Rocks	Filled Weight Freshwater (Including Plants & Rocks)	Filled Weight Saltwater (Including Plants & Rocks)
	Inches	lbs	lbs	lbs	lbs
2 1/2 gallon	12″ x 6″ x 8″	3	3	26.9	27.4
5 gallon	16″ x 8″ x 10″	7	10	58.7	59.8
10 gallon “Leader”	20″ x 10″ x 12″	11	15	109.5	111.5
15 gallon	24″ x 12″ x 12″	21	25	171.2	174.3
15 gallon High	20″ x 10″ x 18″	22	25	172.2	175.3

MID-SIZED AQUARIUMS
Tank Size	L x W x H	Empty Weight	Plants & Rocks	Filled Weight Freshwater (Including Plants & Rocks)	Filled Weight Saltwater (Including Plants & Rocks)
	Inches	lbs	lbs	lbs	lbs
20 gallon High	24″ x 12″ x 16″	25	30	221.9	226.1
20 gallon Long	30″ x 12″ x 12″	25	30	221.9	226.1
25 gallon	24″ x 12″ x 20″	32	40	280.6	285.9
29 gallon	30″ x 12″ x 18″	40	45	327	333.1
30 gallon Breeder	36″ x 18″ x 12″	48	48	346.4	352.6
40 gallon Breeder	36″ x 18″ x 16″	58	60	451.8	460.2
40 gallon Long	48″ x 12″ x 16″	55	60	448.8	457.2

LARGE AQUARIUMS
Tank Size	L x W x H	Empty Weight	Plants & Rocks	Filled Weight Freshwater (Including Plants & Rocks)	Filled Weight Saltwater (Including Plants & Rocks)
	Inches	lbs	lbs	lbs	lbs
50 gallon	36″ x 18″ x 19″	100	70	587.3	597.7
55 gallon	48″ x 13″ x 21″	107	75	641	652.5
65 gallon	36″ x 18″ x 24″	126	90	758.5	772
75 gallon	48″ x 18″ x 21″	140	110	875.9	891.6
90 gallon	48″ x 18″ x 24″	160	120	1031.1	1049.9
125 gallon	72″ x 18″ x 21″	206	130	1379.2	1405.3
150 gallon	72″ x 18″ x 28″	338	140	1729.8	1761.1
180 Gallon	72″ x 24″ x 25″	350	170	2022.2	2059.7
225 Gallon	72″ x 27.5″ x 27.5″	360	190	2427.7	2474.7

Based on saltwateraquarium.com.

The manufacturers often mention the volume of every aquarium to easily estimate the required volume of water to fill the tank. If it's not written, then you may subject the aquarium calculator to perform the precise calculation. It is equipped with the respective volume formulas for various aquarium shapes.

FAQ’s:

Does Shape of The Aquarium Impact Its Volume?

Yes, each shape has a different volume formula. For example, the formula of a rectangular shape depends on the length, width, and height, whereas a cube formula relies on its length.

What Happens If Fish Tank Is Too Small?

The Significant drawbacks include the quick occurrence of problems because of the small size of the fish tank. Because of the limited water volume swift temperature changes can happen, affecting the overall health of the fish.

Are Bigger Aquariums Easier To Maintain?

Yes, definitely! A large fish tank provides a proper ecosystem with a built-in facility for self-cleaning. That is why the huge water volume and temperature remain stable enough to keep the environment life-friendly for your fish.