How Long Does It Take For A Leopard Gecko To Reach Full Size?

For those new to owning and caring for a leopard gecko, you may not know what an adult looks like versus a juvenile or baby. How long does it take for a leopard gecko to reach full size? How big are they going to get? Are there differences when it comes to caring for a young leopard gecko versus an adult gecko? When leopard geckos reach maturity, some things do change.  Let’s take a look at determining the age of your leopard gecko and some of the things you have to consider when your gecko reaches adulthood.

When do Leopard Geckos Reach Full Size?

Leopard Geckos generally reach full size by 18 – 24 months old. While they are considered to be adults at one year old, many still continue to grow for another six to twelve months. Even past that, your gecko will continue to shed and grow slightly in weight and length throughout its life, but probably not in a noticeable way.

Just like humans, leopard geckos will grow at slightly different rates from one gecko to the next. We put together this chart of the average ranges in weight and size of leopard geckos for their first two years of life.  Hopefully this will help you get a better understanding of what to expect in terms of growth.

Age Weight Length
Birth 3 – 4.5 grams 3 inches
0 – 2 months 3 – 20 grams 3 – 4 inches
3 – 6 months 20 – 40 grams 4 – 6 inches
6 – 12 months 40 – 65 grams 6 – 8 inches
12 – 18 months 65 – 100 grams 8 – 12 inches

Like stated above, these are rough estimates, so keep that in mind when measuring your gecko.  If you’re good about taking care of them properly and they are and have been healthy and stress-free within those first 12 months, then your gecko should match up with the numbers above fairly closely.

When do Leopard Geckos Reach Adulthood?

Leopard geckos are considered to have reached adulthood when they reach 12 months (1 year) of age and weigh about 40+ grams. However they may reach sexual maturity (able to reproduce) before they are one year old. Their sexual maturity relies more on their weight than their age. Typically a leopard gecko must grow to 35-40 grams to reach sexual maturity and this can happen as early as 6-8 months old for some geckos.

While there are some changes that take place as far as your gecko’s personal needs go, none of these changes are too major to the point where it makes raising and caring for them any more difficult.  The only real difference between a baby geckos needs and an adult’s geckos needs are slight diet changes and larger tank equipment. Let’s take a deeper look into their aging process.

What Is The Lifespan of a Leopard Gecko?

A good average to go by is anywhere from 6-10 years.  But with the proper care, they can easily live up to 10-20 years and sometimes even beyond that.  There’s really no possible way you can tell how long your individual leopard gecko(s) will live, but if you care for them the way all good owners should, then the chances of them living a long and happy life are very high.

Compared to other smaller animals, leopard geckos can live a surprisingly long time.  A lot of them will grow with you all the way up into adulthood and can serve as amazing little companions as the years go by. Of course, just like the rate at which they grow, certain factors will determine how long each one will survive.  These factors are usually things like how healthy they are over the span of their life and also maybe even some genetic factors.

Tank Size for Adult Leopard Geckos

For an adult leopard gecko, you want a tank size of 10 gallons minimum, but 20-30 gallons would be optimal.

We always recommend starting out with a 20 gallon tank, no matter what the age of your gecko. Having a larger tank is fine for babies and you won’t need to keep swapping it out for something bigger as they grow. That saves time, space and money in the long run, even if it seems like a big investment up front. At this size you will also have plenty of room for all the necessary hides and accessories they will need, plus room to really decorate their little habitat if you’d like to. 20 gallons is also a good size if you intend to try and introduce a second leopard gecko to the same tank.

The one I use and always recommend is the Eco Terra Glass Terrarium. It’s 20 gallons, has multiple neat specs and features, and is even safer for your gecko because it opens from the front.  I say that because picking them up from above can spook them and, therefore, cause them stress.

Another great thing about this specific tank is that when you open the front doors, there’s actually a bit of raised glass that disallows them from escaping.  Which is even better for leopard geckos because they can’t climb simply due to the fact that they don’t have sticky feet like other lizards.

Feeding Your Growing Leopard Gecko

Any logical person would naturally think that the more they grow, the more they’ll eat.  But with leopard geckos, it’s actually quite the opposite. They eat more frequently when they are young because they need the vitamins and nutrients to growth, and they grow quickly in those first 6 months.

Feeding Frequency with Calcium + D3 + Vitamins

  • 0-6 Months Old = Everyday
  • 6-12 Months Old = Every Other Day
  • Over A Year Old = Every 3-4 Days

How much they eat during feeding times will be completely dependent on your gecko.  You should dust your feeder insects with calcium and D3 first. You can put them in a ziploc bag or container and shake them around with the vitamin powder until coated, then feed.

As far as what you should feed them, that completely depends on you and your leopard gecko’s personal preference.  Many owners will keep them on a pretty strict cricket and mealworm diet with the exception of a few other foods that are used as treats.  Don’t worry, leopard geckos don’t have a problem eating the same types of food over and over again.

But, whatever you do, make sure the food you’re giving them is alive.  Dead bugs are not appealing to leopard geckos, and without movement, sometimes they won’t even touch it.  There have been a few instances where I’ve seen others recommend a vibrating feeding dish, but unfortunately, not many have seen a whole lot of success with these, so I personally wouldn’t recommend it.

How Much does an adult leopard gecko cost?

An adult leopard gecko that is not a specialty morph usually costs about $20 – $40 dollars.  We have seen them at PetCo for $35.00 and at PetSmart for $30.00. If you are looking into buying a specialty morph, the price range can vary immensely depending on exactly what morph they are. The same goes for baby and juvenile leopard geckos, you are looking at about the same price range.

Where the price usually kicks up a bit is when buying the equipment, but considering the lifespan of these little guys, the cost of the initial set up is a very small investment.  I mean, you could potentially be the owner of one to up to 30 years, so I think it’s safe to say that it’s totally worth it.

Upkeep and items that you will need to replace more frequently, such as substrate and food, will usually last you a very long time and neither of which will break the bank whenever it’s time for you to re-up on your supplies.

If anything, though, adult leopard geckos are lower maintenance and a little cheaper to care for than babies or juveniles because of the fact that they require less food.

Where to Buy an Adult leopard Gecko

There are many different places to purchase an adult leopard gecko, but the first place that most people go to is their local pet shop. Leopard geckos are common enough that large pet store chains such as PetCo and PetSmart will carry them. Even smaller local shops that carry fish often also carry reptiles and small mammals.

However if you cannot find a place locally, you can always buy online.  You would think that safety would be a concern when shipping geckos. But most of the more reputable online stores have lots of experience in the best shipping practices to make sure your pet gets to you safe and healthy. However, because of these extra shipping precautions and costs, buying online can end up being a lot more expensive (I’m talking $150-$200!).  So, if possible, call around and see if you can find a local shop that carries them.

Just make sure before buying one to do your research and read reviews.  There are companies out there who don’t handle and care for their leopard geckos or insects properly.

How to Tell If They’re an Adult

Sometimes when receiving leopard geckos, it can be hard to tell whether they’re still an adult or a juvenile if you haven’t had much experience with them.  This can happen if you’ve adopted, rescued, or were gifted one by a friend or family member.

A lot of the time, people will determine a leopard geckos age based on their weight, but if they’re a rescue gecko with a disease or infection, then this can sometimes be very difficult to tell.  That’s because a lot of these various illnesses and diseases can actually cause your leopard gecko to lose weight fairly rapidly, which can then result in death if it gets too bad.  That’s a whole different topic, but if you happen to be a rescuer of a leopard gecko, then I suggest checking this article out where we identify and discuss different illnesses and diseases.

An easy way to weigh them is to purchase a food scale.  Food scales are meant for weighing very light substances such as powders, so having this type of scale for your gecko will be adequate in giving you an accurate reading. If they weigh anywhere from 40 – 100+ grams, then they’re likely an adult.

Aside from weight, you can check their length by measuring them with a ruler.  As listed in the chart above, you can see that they will usually meet certain lengths depending on age, with adults being about 7 – 10+ inches.  Checking both either weight and length will give you the best idea on their age.

Can you have a leopard gecko tank that is too big?

Not necessarily.  As long as you’re able to spread your temperatures out evenly just as you would with any other tank, there shouldn’t be a problem.  Now, I wouldn’t go and put them in a tank that’s 100 gallons, but I have heard of others comfortably putting their leopard geckos in tanks that are up to 50 gallons and sometimes even a little bit more without any issues.

There is one downside to having a tank that large, and that’s having to buy more substrate.  Substrate is fairly cheap and usually doesn’t have to be replaced more than once a month, but when you do buy it, you’ll likely have to buy a lot more.

If you have multiple leopard geckos, then it makes sense to have a tank that’s 30 – 50 gallons.  But if you only have one, you can just stick to 10-20 gallons until you’re ready to expand in the future once you’ve gained some experience with your first gecko.


As you see, leopard geckos, along with other animals, reach adulthood fairly quickly.  The good thing, though, is that not a lot changes as they get older.  This can be worrisome for those who want an animal that is low maintenance, but with leopard geckos, there’s really nothing to worry about as they get older.

After all, entering adulthood actually has many benefits.  Fewer sheds, less food, and therefore less stress on you and them.  Should you buy a leopard gecko when it’s already an adult? Sure, but it might be a little more difficult to tame them.

Just keep in mind that adult geckos need a lot more space than babies, so it’s important to get them the right equipment so that they can live comfortably.  Equipment that isn’t meant for them or that is too small for them can cause a great amount of stress and, in return, cause out-of-the-ordinary behaviors and even a higher susceptibility to certain diseases and illnesses.

I’m Devin Nunn, an average joe that just so happens to have a deep love and passion for everything to do with reptiles. Because taking care of them for the vast majority of my life wasn’t fulfilling enough, I decided to begin educating others about them through my articles. read more...