How to Tell How Old a Baby Rabbit Is: Key Clues & Chart

Figuring out how old baby bunnies are can be difficult, but understanding their growth stages helps you estimate their age.

Updated July 21, 2023
Boy holding box with young rabbits.

Figuring out a bunny's age just by looking at them is tough. But it's important to know, because caring for young rabbits changes as they get older, and their care needs change rapidly early in life.

Whether you're a pet parent or have found baby bunnies in your backyard, understanding how old they are is critical for their survival and well-being. Rabbit lovers use size and weight for an age estimate, but it's still a guess! Grab a journal and write down some critical observations about your baby bunny to make a guesstimate.

How to Tell How Old a Baby Rabbit Is

The size and weight may help rabbit owners determine an approximate age. When bunnies are born, their eyes are still closed and do not open until closer to ten days. Diet is one reason it is essential to know how old the baby bunny is, and at seven weeks, a rabbit may start eating pellets and grass hay.

Quick Tip

If you find a wild rabbit, regardless of their life stage, a veterinarian or wildlife rehab specialist will give them the best chance at survival.

Baby Bunny Age Chart

The criteria for the five key ages are weight, length, overall size, and some distinct physical features. Some rabbit breeds vary slightly. For example, the Flemish giant breed may weigh between 14 and 20 pounds. Some dwarf rabbits only weigh two pounds! Adults are typically 15 to 20 inches tall, but this also varies depending on the breed.

  • Newborn - around one ounce and eyes are shut
  • 5 to 10 days old - eyes are open or opening, and the baby can fit in the palm of your hand
  • 2 to 3 weeks old - the size of a gerbil with fur growing in
  • 4 to 5 weeks old - bigger than a softball and five to seven inches long
  • 6 months old - two to three pounds
Baby Bunny Age Chart

Growth May Be Dependent on Breed

Your baby rabbit may be in one of four breed categories: giant, medium, small, and dwarf. Adult weights vary for larger breeds. Some rabbits are giant, and others are a dwarf breed and tiny. The following breeds show the differences in weight between them.

Netherland Dwarf

The adorable Netherland dwarf rabbit only weighs two pounds as an adult. This breed is popular. Pet owners enjoy the rabbit's apple-round head and short ears.


The Rex breed's fur is like velour. This breed is a medium-sized rabbit and weighs eight to nine pounds as an adult.

Flemish Giant

At eight to nine weeks, this breed weighs five pounds. From eight weeks to eight months, the rabbit may gain 0.5 to 0.75 pounds each week and is not considered full-grown until 14 months of age. The adult weighs about 14 pounds.

Need to Know

It can be difficult to age a newborn bunny, but due to their rapid growth in early stages, key differences can be found quickly.

Baby Bunnies Enjoy a Good Chew

At around seven weeks, it is appropriate to introduce alfalfa and grass hay to your baby bunny. Watch your bunny as this small pet is ready for a good chew! When you check the age range, be sure to mark your calendar as this milestone is a big deal for your baby rabbit.

Visit the Vet for the Exact Age

An exotics vet specializing in small animals needs to do an exam to determine your bunny's age. Your guess based on the chart is probably very close, but a vet may help with questions related to diet and overall breed traits. Diet is key for a growing rabbit, so the bunny must be eating an appropriate pellet feed.

How to Tell How Old a Bunny Is

Typically, a new baby rabbit's age may be determined by size and weight. The eyes are still closed before ten days, and there are features to help uncover an approximate age range. Pet parents may want to visit a vet to verify the age as there are essential diet changes during the growing phase, and a missed step may impact the health of the bunny.

How to Tell How Old a Baby Rabbit Is: Key Clues & Chart