All About Fish Tank Weight and Dimensions

Choosing the right aquarium isn’t always easy, especially if you are a beginner. There are many things you need to consider, like the material, size, shape, type of fish. But the dimensions and the fish tank weight are on top of the list. You need to know exactly how heavy the tank will be and what footprint it has, so you can find the perfect spot for it and start planning everything else.

The weight of your future fish tank is important because it will affect its location and can cause some handling issues. For example, it could be too heavy to place it on a piece of furniture, and you will have to buy a dedicated stand. It could also be too heavy for you to set up by yourself. Or you won’t be able to move it once it’s filled with water. So here is the fish tank weight and the dimensions for every category, to help you decide which one is best for you.

Small Aquariums

Weight and dimensions are less likely to cause any problems in this category, but it’s still important to know them before making a purchase. Even within the ‘small’ section, there is a significant difference in size between aquariums. For instance, a 15-gallon fish tank is much larger and heavier than a 5-gallon piece.

Before getting to the actual numbers, we feel it’s important to underline that the small aquariums should only be chosen if you really cannot get a bigger one, for different reasons. They will be less comfortable for the fish, giving them less space to swim. At the same time, if we consider the hassle for the owner, a larger tank is much easier to maintain, so keep that in mind when you decide on the size.

Small tanks are only suitable for small fish, and only a few of them. In fact, if you buy a 2.5-gallon tank, you should probably have only one fish. On the other hand, the standard 10 gallon aquarium dimensions will give you a bit more freedom. So, to be able to plan everything and choose the best aquarium for your home, take a look at the following table to see the details:

Tank sizeL x W x HEmptyFilled
2.5 gallon12” x 6” x 8”3 lbs.27 lbs.
5 gallon16” x 8” x 10”7 lbs.62 lbs.
10 gallon20” x 10” x 12”11 lbs.111 lbs.
15 gallon24” x 12” x 12”21 lbs.170 lbs.
15 gallon high20” x 10” x 18”22 lbs.170 lbs.

Small aquariums aren’t usually the right choice for beginners. However, if space really is an issue and you still want a decent environment for your fish, choose one as large as you can within this category. Now that you know what are the dimensions of a 10 gallon aquarium, you can check if you have room for it, to give your fish a little more volume to swim around. If you only have room for a tiny one, you won’t have to worry about also getting a stand. The weight of 5 gallon fish tank can be supported by any piece of furniture.

Also read – How to Build Your Own DIY Fish Tank – A Step by Step Guide

Mid-Sized Aquariums

The fish tank weight and dimensions in this section are larger, but these aquariums are more suitable for beginners. They are easier to maintain and allow you to have more than a couple of fish without making them uncomfortable. The 20 gallon long aquarium dimensions, for example, make it very easy to clean and aquascape, and your fish will have a nice length for swimming. If you check what are the dimensions of a 40 gallon breeder aquarium, you will see that it has a footprint that makes it easier to place; it will also look larger than it actually is, so the visual impact is higher. And if you take a look at the 30 gallon fish tank weight, you can see that if you have a sturdy piece of furniture, you may not have to buy a stand, even if this isn’t such a small aquarium. Now let’s take a look at all the fish tank weight and dimensions in the middle-sized category:

Tank sizeL x W x HEmptyFilled
20 gallon high24” x 12” x 16”25 lbs.225 lbs.
20 gallon long30” x 12” x 12”25 lbs.225 lbs.
25 gallon24” x 12” x 20”32 lbs.282 lbs.
29 gallon30” x 12” x 18”40 lbs.330 lbs.
30 gallon breeder36” x 18” x 12”48 lbs.348 lbs.
40 gallon breeder36” x 18” x 16”58 lbs.458 lbs.
40 gallon long48” x 12” x 16”55 lbs.455 lbs.

Large Aquariums

This is definitely the most impressive category, and if you look at the 150 gallon tall aquarium dimensions, you will see what we mean. These large aquariums give you so many possibilities when it comes to stocking and aquascaping. The larger ones may not fit in any home, but the standard 55 gallon aquarium dimensions will probably go very well in your living room. They will be more difficult to handle sometimes, and the fish tank weight will demand a dedicated stand, but the result will be outstanding.

And if you have space, go bigger! Just make sure you get a stand that’s sturdy enough to handle the 150 gallon fish tank weight without bowing in time. In fact, if you choose a huge aquarium, you may have the surprise to discover the floor may also be affected by the fish tank weight. So apart from getting a solid stand, you may also have to reinforce your floor.

And there are even more aspects you need to consider. If you check what are the dimensions of a 180 gallon aquarium, you will see it’s not that easy to place even in a large room. You will need to leave some space between the stand and the wall, to fit all the wires, filters, and so on. You also want to have the storage cabinet somewhere close to the aquarium, to make the maintenance easier. At the same time, such a big tank should go in a room where people can fully admire it, but without having too much traffic around it, to avoid accidents. Even the dimensions of a 125 gallon aquarium require quite a lot of space.

That being said, if you are a passionate aquarist, this is the category for you. You will be able to have bigger fish, more of them, and genuinely spectacular decor. If the 50 gallon long aquarium dimensions are more than decent, imagine having a larger one. But before choosing one, take a look at this table to see the exact fish tank weight you should expect.

Tank sizeL x W x HEmptyFilled
50 gallon36” x 18” x 19”100 lbs.600 lbs.
55 gallon48” x 13” x 21”78 lbs.625 lbs.
65 gallon36” x 18” x 24”126 lbs.772 lbs.
75 gallon48” x 18” x 21”140 lbs.850 lbs.
90 gallon48” x 18” x 24”160 lbs.1050 lbs.
125 gallon72” x 18” x 21”206 lbs.1400 lbs.
150 gallon72” x 18” x 28”308 lbs.1800 lbs.
180 gallon72” x 24” x 25”338 lbs.2100 lbs.
225 gallon72” x 27.5” x 27.5”358 lbs.2158 lbs.

There is also the extra-large category, but those aquariums are not likely to fit in a standard home. A 500 gallon fish tank weight is not suitable for most locations.

Also read – Glass vs. Acrylic Aquariums – Which One is a Better Choice?

Why Is it Important to Know the Fish Tank Weight and Dimensions before You Buy it?

As we have shown before, the fish tank weight is a crucial aspect to consider. If a small one can easily go on your nightstand, the weight of a filled 120gal fish tank is much harder to support. But it’s not all about the fish tank weight; the dimensions are also essential. Not only will a large aquarium be harder to place in your home because it takes a lot of space, but it’s also more expensive when it comes to maintenance.

A large footprint means you will have to use more substrate. Also, the dimensions of a 125 gallon aquarium, for instance, require a more elaborate lighting system, special filters, maybe two of them, as well as other equipment. So, you need to add those expenses to the budget as well.

The footprint also affects your stocking options. The dimensions of 10 gallon aquarium don’t give you much freedom, but a larger water surface means you can have more space for your fish. Apart from that, the dimensions of the tank are also connected to the weight distribution, so measure twice before choosing the stand or piece of furniture you want to use.

How to Calculate the Fish Tank Weight for Unusual Shapes

There are certain situations when you only have the dimensions and don’t know the fish tank weight. It happens when the aquarium has an unusual or custom made shape. Maybe you received an old aquarium that’s still in good condition, or you bought a hexagonal piece and have doubts about how many gallons it holds. Or you don’t know how heavy it will be once filled with water. What you need is an aquarium dimensions to gallons calculator. Once you have the volume, it’s easy to know the weight, since a gallon of water weighs 8.34 lbs. So, this fish tank weight calculator is a handy tool. Just enter the dimensions of your tank and click ‘Calculate’:

Aquarium Tank Volume Calculator

FAQs on Fish Tank Weight and Dimensions

How are dimensions listed on an aquarium? As seen in our tables, the dimensions of an aquarium are listed as L (length), W (width), and H (height).

How much weight can a fish tank hold on top? The lids and canopies that come with the aquariums are specially designed so they won’t apply too much pressure on the walls and affect the overall integrity. That’s why it’s better to buy a set or at least a top that’s made precisely for the tank you have. If you want to make one yourself, it’s more tricky. To get an idea of how heavy it can be, the top of a 55-gallon aquarium shouldn’t hold more than 10 lbs. in the long run.

What are the Aqueon 65 gallon aquarium dimensions? The 65-gallon tank from Aqueon is an excellent choice for a large home aquarium. Its dimensions are 18.4” (L), 36.4” (W), 25” (H).

What dimensions would be ideal for a turtle aquarium? If you are planning a turtle aquarium, the rule of thumb is 10 gallons of water for every inch of the turtle. So, you will need a pretty large tank.


The fish tank weight is one of the most important aspects to keep in mind when you are looking for your next aquarium. Paired with the tank dimensions, it will affect the location, the stand, the cost of maintenance, as well as your options when it comes to aquascaping and stocking it. You may not realize just how heavy an aquarium will be once you fill it with water, so these tables will make it easier to choose the right one.

Also read – Self Cleaning Fish Tanks That Actually Work

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