How Big Do Mollies Get: Size Guide | Aquascape Addiction

How Big Do Mollies Get: Size Guide

Wondering how big do Mollies get? we cover the growth sizes of the common 11 types of molly fish along with some helpful care tips.

How Big Do Mollies Get: Size Guide

Mollies are some really cool fish no doubt. They are bright, colorful, and very active too. They are great to have in any home aquarium, even larger community aquariums with many different types of fish. However, before you go out and buy any kind of Molly fish, you probably want to know a few things about this species first.

You need to know basic fish info before making a purchase, which is why we are here today. “How big do mollies get?” is the main question that we are here to talk about today.

So, How Big Do Mollies Get?

One thing that you need to beware of is that there is no single answer to this question. This is because there are actually several variations of the Molly fish, all of which have different coloration, different sizes, and more.

What we can do is list all of the different kinds of Molly fish and tell you how big each of them get. This way you might be able to come closer to a purchasing decision. Heck, maybe you would like to get more than one type of Molly.

Dalmatian Molly

This black and white spotted variety of Molly can grow to around 4.75 inches in length.

Dalmatian Lyretail Molly

This type of Molly fish looks very similar to the normal Dalmatian, except it has a bit of yellow, plus a uniquely shaped tail. This fish can grow to around 4.75 inches in length.

Black Molly

This Molly fish is simply black. It doesn’t have any other colors, but it definitely looks interesting. The Black Molly can grow to around 3 inches in length.

Black Sailfin Molly

This is one of the larger Molly varieties out there. It can grow to around 6.5 inches in length, is black in color, and as the name implies, has a cool sail-like fin.

Black Lyretail Molly

This is another fairly large type of Molly fish. The black lyretail is a mysterious little guy that can grow to around 5 inches in length.

Gold Dust Molly

As the name implies, this fish is bright golden yellow in color, kind of like a goldfish. This guy can grow to around 5 inches in length.

Balloon Molly

The Balloon Molly is one of the smaller Molly fish out there. It looks like a little rounded balloon with yellow and white stripes. It can grow to around 3 inches in length.

Marble Lyretail Molly

This peaceful Molly fish has a really nice blue, white, and black marbled pattern. It can grow to around 5 inches in length.

Gold Doubloon Molly

This particular Molly has a really neat color scheme, with the rear being totally black and slowly turning to a bright golden color as you move towards its head. The Gold Doubloon Molly can grow to around 5 inches in length.

Harlequin Sailfin Molly

Yet another Molly with a neat sail like fin, plus an awesome marbled color scheme, this thing will grow to around 6 inches in length.

Platinum Lyretail Molly

This platinum colored Molly is one of the more interesting looking ones and it can grow to roughly 5 inches in length.

Golden Sailfin Molly

This species of Molly looks like a mix between a sailfin Molly and a goldfish. It can grow to roughly 6 inches in length, with the males being substantially larger.

Some Molly Care Tips

If you want your Molly fish to be happy, healthy, and grow to its full potential, there are a couple of tips that you should follow.

Make sure that you have a large tank. Mollies like to have a ton of space. For instance, a Molly that is around 5 inches in length will require something like a 30 gallon tank. The more space they have, the higher the growth potential.

Make sure to keep the water clean, do regular water changes, and make sure to have a good filtration unit. Simply put, it’s harder to grow big and strong when you live in a polluted environment.

Make sure to feed these fish a proper diet. You need to give them a good mix of nutritionally balanced foods in order to increase their growth potential, increase their bright colors, and to make sure that their bodily functions work properly.


The fact of the matter is that there are a dozen or more varieties of Molly fish out there. They are not all the same size, but generally speaking, they will be no shorter than 3 inches and no longer than 7 inches in length. If you take good care of them and follow the tips we have outlined above, the chances of your Molly reaching its full size is greatly increased.