Medium size fish aquariumAquarium Dimensions are influenced by the different number of animals you intend to keep. For example, some fish tanks are too bulky, and your house floor may not support them.

Other aquarium types require you to allocate more space for accessories like water inlets, heaters, or filters.

Read this article to acquire an in-depth understanding of aquarium dimensions and the right fit for your home.

Aquarium Sizes

Knowing about the different aquarium sizes is essential while setting up a fish tank in your home or office. It is the most critical decision to make because it helps narrow down your thoughts.

It analysis information like;

  • Type of fish to get; some fishes need a lot of space to thrive
  • Gallons of water the aquarium can contain
  • Aquarium weight
  • Other area considerations like the place you plan to put the aquarium

You should have enough room in front of the aquarium to reduce the probability of a freak accident. Also, you should leave space in between the wall and behind the aquarium.

The sides are not left out; you want the aquarium to be away from other live loads in the room but not too far that it looks awkward in a corner. Live loads are moveable items in a room like room decorations, furniture, shelves, etc.

Standard Aquarium Sizes

A standard aquarium is primarily:

  • A traditional rectangle tank.
  • Its manufacturers fabricate it mostly from glass.
  • It is silicon-sealed with a base and rim support fashioned from plastic materials.
  • The standard aquarium glass thickness ranges from 0.375 to 0.5.

However, tanks from 40-gallon size and above are made by their manufacturer with extra centered rails. So to measure a standard tank, you must estimate it from the outside to the plastic support base. Nonetheless, brands have different dimensions for their standard fish tanks, but they all share similar specifications.

For example, a standard 10-gallon capacity aquarium should have a typical weight of 111 pounds, including a gravel substrate at the tank’s bottom, and it’s filled with water. Its length measurement should be 20 inches, its breadth 10 inches, and its height of 12 inches.

Pros of a Standard Aquarium

A standard fish dimension is easier to calculate than a custom-sized aquarium because it does not come in various styles. It is functional with a classic design, unlike custom aquariums which are primarily massive in size. The standard-sized tanks have a lot of information on different websites which you can easily access.

Furthermore, you can measure your proposed fish tank space and look through the dimensions to estimate which aquarium suits your needs, like what an empty or full aquarium weighs and its durability.

Standard US-Gallon Aquarium Sizes

The aquarium sizes in the United States are measured in gallons, unlike the other parts of the world that uses liters. Below are some primary fish tank sizes.

1. Small-Sized Fish Tank

Small aquariums’ dimensions start from a two and half-gallon capacity. In most cases, you do not require a tank stand as you can place them on your work desk or any level surface around your home. The “largest” small-sized tank aquarium available in the US would contain about 15-gallons of water.

However, small aquariums are not ideal for a beginner fish-keeper because they are challenging to maintain. But it doesn’t make it less popular amongst the beginner group.

2. Medium-Sized Standard Fish Tank

The medium fish tank is the best option for a beginner fish-keeping enthusiast. They are affordable as they cost little to install, plus they have outstanding filtration and require minimal care. The medium-sized aquarium dimensions start from about 20-gallon of water to a 40-gallon volume. They do not have high-risk factors that would affect your fishes, unlike the small aquarium.

However, they weigh a lot more than the smaller tanks, so you must get an aquarium stand.

3. Large Standard Fish Tank

A large-sized standard aquarium has its least capacity at 50 US gallons to its largest volume of 200 gallons. You have to plan and think about how to utilize and maintain a large standard fish tank fully. They would also need a sturdy aquarium stand plus an aquarium lid. You must ensure you have space for tank accessories such as a standard filtration system or heater.

4. Extra-Large Standard Fish Tank

Most extra-large tanks are custom-built aquariums. They are usually as large as 180-gallon capacity, which is not a typical standard aquarium dimension. However, each brand has its features, and its manufacturers fabricate most extra-large fish tanks from durable yet lightweight materials such as acrylic.

They also come with custom-made holes for filters and rounded edges. Nonetheless, you should consult with different manufacturers to decide which model meets your needs.

Factors to Consider When Choosing the Adequate Aquarium Dimensions

Fish aquarium with adequate dimensionsWhen choosing the appropriate aquarium for your fish pet, you should pick the Tank with the correct dimensions and design.

It is crucial to remember that bigger fish tanks are easy to care for, and it is an excellent selection for beginner aquarists. This is because small aquariums have small surface areas, and in case of a disease breakout, it would spread faster if you were not observant. A beginner may have little experience in how to tackle the problem.

Here are other factors to consider:

– Tank Size

You have to get an aquarium whose size fits into the room or space you have planned. It is crucial to point out that the fish tank dimensions influence its weight. Also, do not conclude based on its volume capabilities; for example, not all nonstandard-sized 10-gallon aquariums can take 10 gallons of water.

They may have rounded edges or a complicated design that takes up space, while others weigh more even when empty. To prevent your fish tank from collapsing due to incorrect aquarium dimensions or wrong assumptions, overrate the aquarium weight. Also, note that the water, tank decoration, substrates, and other accessories would influence the aquarium’s overall weight.

– Aquarium Substrate

The aquarium substrate’s ideal weight is roughly one pound to one gallon of water.

However, the weight calculation differs in some cases. For example, if your aquarium is an aquascaped model, you would need to use either less or more sand or gravel substrate, just enough to cover the bottom of the tank and grow healthy aquarium plants. When you add the weight of substrates and plants to a 10-gallon standard fish tank, it can be about a 120-pounds weight.

– Gallon Capacity

Determining how much water a gallon holds is essential. However, the conversion of one gallon of water to liters differs based on density and measurement. In America, one gallon of water is calculated as 3.785 liters, but the UK measurement is different. A gallon in the UK is 4.546 liters, so you need to know which volume your proposed aquarium would take.

– Type of Aquarium Water

It is common knowledge that salt water is more dense than freshwater due to its saline content. The water temperature, chemical composition, and salinity influence the weight of water in an aquarium. For example, if a gallon of fresh water weighs 8.345 pounds, then the same quantity of saltwater would be 8.554 pounds.

– Species of Fish; Freshwater Fish or Marine and Euryhaline Fish

The fish type can determine your fish tank measurement. A freshwater or a saltwater fish tank differs in the aquarium dimensions. Your aquarium community’s size may have to reduce so that the Tank can peacefully contain them.

– Freshwater Aquarium

Freshwater fish tanks require minimal care and setup, so they are a perfect choice for the novice aquarist. It is a popular opinion to measure freshwater aquarium content as one inch of fish to one gallon of water. However, it may not be a trustworthy guide for all freshwater fish species.

For example, a Neon Tetra grows to about one and a half inches in body size, yet they require a 10-gallon standard aquarium. It is because they thrive better in large groups. Other fish species may require less space, like the guppies. They need a tank with an aquarium dimension of 5-gallon volume.

– Saltwater Fish Tank

Saltwater aquariums are more expensive, and they need accessories like aquarium lights, chillers, etc. They are also more challenging to install or manage; they are ideal for seasoned aquarists with adequate fish-keeping backgrounds.

Furthermore, steps you would consider essential, like filling the aquarium with water, are not straightforward. You need to consider the water’s salt content. Some marine or euryhaline fishes also need a lot of space due to territorial traits or the need to swim around to keep fit. Maintaining saltwater aquariums costs more generally from purchasing the fish to the specific tank requirements.

Aquarium Size Chart

Fish Fish Size Minimum Aquarium Size
Tiger Barb 4 inches 24 inches
Clown Pleco 8 cm 36 inches
Black Molly  6 inches 30inches
Harlequin Rasbora 5 cm 20inches
Jack Dempsey 10 inches 48inches
Red Tail Shark 6 inches 36inches
Keyhole cichlids 4¾ inches 28 gallons

How Aquarium Dimensions Affect A Building Structure

The average floor weight for live loads in America is measured as pounds per square foot. For example, referring to the US building code, the average live load for a warehouse is between 150-200 pounds per square foot (PSF). In comparison, 50 pounds per square foot is allocated to offices and 40 to apartments. This means that your house can comfortably carry 40 psf of live load. Remember that live loads are moveable items like furniture in your home.

However, it is crucial to note that the 40 psf is not concentrated in one part of the room but spread out over the house from walls to floors uniformly. The apartment pound per square meter measurement is an average standard reading building Engineers refer to while building a house. Please note that there’s a difference between live load weight and floor pressure. The pressure is not a primary factor like the weight, which on the other hand, stresses the main building structure.

You can put Fish tanks from the 55-gallon volume at any house position, but a 125-gallon would be best at a strategic position. You do not want your floors to develop critical framing defects because of your aquarium.

For instance, you can place a 125-gallon aquarium with a sturdy wooden aquarium stand without support near a bearing wall, yet make sure it is perpendicular to the apartment’s joist. Nonetheless, an aquarium dimension that is more than 125 gallons would need extra support, or it would gradually damage your wood floors after a while.

Let’s debunk two popular myths beginner aquarists may have.

– Myth 1

“Since I placed my aquarium in my room, my floor appears to be vibrating.”


Your aquarium is a stationary live load; it is not bouncing; instead, it reduces its floor vibrations caused by foot movement. You only notice the vibration more because of the water ripples in your aquarium.

– Myth 2

“I put in a rock that weighs 210 pounds into my fish tank. Now my aquarium has an additional weight of 210 pounds.”


Rock remains the same weight on land, but in the water of about 1.5 cubic feet, the rock would have a buoyant weight of 116lbs!


  • Fish aquariumAquarium dimensions are crucial information to have while selecting the best fish tank for your home or office.
  • The fish type and quantity, substrates, and water type are considered factors when purchasing a fish tank.
  • A standard with an aquarium dimension of 10-gallon may not have the same capacity as a custom-made fish tank.

Aquarium dimensions are necessary as they tell you if a tank can fit in your room. You should follow the tips we discussed in this article as they would guide you during an aquarium purchase.

5/5 - (15 votes)


Please enter your comment!
Please enter your name here