When Do Bunnies Stop Growing?

You may be wondering when your bunny will stop growing. As a baby, we noticed our bunny Groot would grow from week to week. In the process outgrowing some of her toys and not being able to fit in some of her favourite spaces!

Smaller breeds stop growing at around 6 months whereas larger breeds can grow to 18+ months. When a bunny stops growing is determined by their individual genetics and nutrition.

While each breed has an average weight range they reach when fully grown, each bunny will differ in their growth rate and final weight. While domestic bunnies are considered adults at one year of age, some may have already reached their full size or still be growing. How do some of these individual factors affect a bunny’s growth?

This table compares the 15 most popular domestic bunny breeds by their full-grown weight, the average age they reach the full-grown weight and their average life span.

Bunny Breed Fully Grown Weight Average Age to Stop Growing Average Life Span
American Fuzzy 3.5-4lbs 6 months 5-8 years
American Rabbit 9-11lbs 6 months 8-12 years
America Sable 8-10lbs 6 months 5-8 years
Beveren 8-12lbs 8 months 5-10 years
Californian Rabbit 8-10.5lbs 8-9 months 5-10 years
Continental Giant 13-35+lbs 18 months 4-7 years
Dutch Rabbit 4-5.5lbs 6-7 months 5-8 years
English Lop 9-10.5lbs 8 months 5-7 years
Flemish Giant 9-14lbs 15 months 5-8 years
French Lop 10-15lbs 9-10 months 5-7 years
Holland Lop 2-4lbs 6-7 months 7-14 years
Lionhead Rabbit 2.5-3.5lbs 6 months 7-10 years
Mini Rex 3.5-4.5lbs 6-7 months 7-10 years
Netherland Dwarf 1.1-2.5lbs 7 months 10-12 years
Polish Rabbit 2.5-3.5lbs 6 months 5-6 years

What Factors Determine a Bunny’s Growth?

Individual genetics play a big role in a bunny’s growth and size. Just like in humans, if your bunny’s parents were on the larger side, then it is likely your bunny will also be on the larger side.

Another factor to consider is that not all bunnies are 100% pure-breds. Rather, your bunny may be a mix of two different breeds making them fall outside of the normal weight or growth ranges.

Nutrition plays the other big role in how your bunny will grow. Like a human baby will have growth problems if not fed the correct food in the correct quantities, baby bunnies will experience the same thing.

If you check out our article and infographic on “What bunnies can eat and not eat,” you will find what to feed your bunny at each stage of growth to ensure optimal health.

As young bunny’s, they should be fed hay that is higher in protein, calcium, and overall calories to fuel their growth. Pellets should be given in unlimited quantities along with hay. This will ensure your bunny at least is minimum in the average range for their breed.

What Do I Do If My Bunny Isn’t Growing?


If your bunny is far behind in weight for where she should be, then there could a couple of factors that are stopping your bunny growing.

  • It’s too hot – If the air temperature is hot, your bunny won’t eat as much.
  • Your bunny doesn’t like the hay she’s being fed.
  • Your bunny is sick. In which case, take your bun to the vet.

There are some easy solutions to the first two problems. Make sure your room is cool especially if it’s the middle of summer and you don’t get any air breeze.

Secondly, if your bunny won’t eat the hay you’re feeding her, try changing the variety to see if she’ll eat it. Some other little tricks are to put hay where your bunny likes to rest or sit. That way it is always around her.

You can also put hay into your bunny’s toys to encourage her to bite, chew and pull the hay. Finally, you can try adding some extra flavour to the hay using bunny safe herbs.

If these tips still aren’t helping your bunny gain weight, then you can also try high protein bunny pellets. These are 18% protein and 3.5% fat. Essentially a weight gaining food for bunnies.

How To Determine Your Bunny’s Age

Sadly this is not an exact science. An experienced vet can give you a pretty good estimate of your bunny’s age. But maybe you have no reason to visit the vet so it’s not worth the money to do so. There is no reliable way to determine a bunny’s age, but here are some tips to help you do it yourself.

  • It is often mentioned that you can check your bunny’s teeth as a sign of their age. An older bunny may have longer, more stained teeth while a baby bunny may have shorter, whiter teeth.
  • However, a younger bunny can have bad teeth and an older bunny can have great teeth. So this method is not a very reliable method to determine your bunny’s age.
  • The skin is a much more reliable method. A younger bunny will have much softer skin while an older bunny will have much tougher skin.
  • Another method is checking your bunny’s hocks or their heels. A really young bunny will have healthy, pink heels (the area of the foot like our elbow) that are fully furred with no calluses. As the bunny gets older, the condition of this hock changes and develops a callus.
  • Use bunny age guidelines to see where your bunny fits. A young bunny is up to 9 months of age. An adult bunny is between 9 months and 4-5 years of age. An elderly bunny is 4-5+ years of age.
  • Use the above table to determine if your bunny is fully grown. While the table provides averages, combining that information with the above tips will give you a pretty reliable estimation of your bunny’s age.

Wrapping Up

The table provided will help you determine if your bunny is on track with their growth. There is always individual variation involved so don’t be too alarmed if your bunny is not in the average range.

However, if your bunny is not growing or well below average, then some intervention may have to be made. If none of the tips above are working, or your bunny is showing other signs of distress other than not eating, then take your bunny straight to the vet.

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