What Size Bed is Right for My Child?

Updated: 8/29/2025

Summary:

• -Match bed size to age and stage: Toddlers do best with low-to-the-ground twin or full beds with guardrails, while older kids can transition to low, mid, or high lofts and bunks depending on their height and climbing confidence. 

• -Choose a bed that adapts: Maxtrix beds are designed to convert and grow with your child from toddler to teen, so that families can adjust layouts and styles over time.

• -Consider growth and safety: Think about your child’s current height and how much they’ll grow in the next few years. Make sure guardrails, mattress height, and ceiling clearance provide a safe and secure sleep space.

 

How Do I Choose the Right Bed Size for My Child?

For kids, it’s an exciting experience to get their own “grown-up” bed. But, as a parent, how do you know what bed type and size is right for your child?  From twin toddler beds to queen-size bunk beds, and everything in between, the options feel endless. 

To help ease your decision, we’ve gathered our top tips and advice to guide parents in selecting the best bed size for their child.

 

Getting Started

When choosing the right bed size for your child, two main factors matter most:

1. Skill level and confidence: Consider how well your child climbs and moves around furniture. Their comfort on a playground can be a good indicator of whether they’re ready for elevated furniture like lofts or bunks.

2. Current and future height: Don’t just think about your child’s size today; also consider how quickly they’re growing. If your child is sizing up fast, it may be worth investing in a bed they can grow into.

While we suggest certain beds for specific age groups, you know your child best. Their abilities and growth rate are important in making the right decision. To get started, measure both their standing height (floor to top of head) and sitting height (seat surface to top of head). Then, compare those measurements to our bed height and headroom dimensions, which will be provided throughout this blog or in our Fit & Measurement Guide.

Pre-K (Ages 1.5 - 4 years old)

When it’s time to transition from crib to bed, choosing a design that sits close to the ground is key. A low-profile bed helps keep little ones safe while encouraging independence as they learn to get in and out on their own. Guardrails are also important to your child’s safety. They keep little sleepers secure and give parents the peace of mind they need.

Starter Bed

Our starter toddler bed is the perfect first step, featuring an ultra-low build and industry-leading 16" guardrails. Plus, the half-length front rail offers the ideal balance: easy independence for climbing in and out, with the reassurance of a snug, safe sleep. 

The starter Maxtrix Twin Bed stands 30.75" tall from the floor to the very top of the frame. Like all Maxtrix beds, it features a solid wood slat base tested to hold up to 800 lbs, so it's strong enough for multiple kids and even parents.

The slat surface sits at 11.75", so the mattress you choose will determine the final sleep height. For younger children, we recommend a 5" low-profile mattress, which brings the sleeping surface to just 16.75" off the ground—an ideal height for a first twin bed.

The best part about our starter bed? It grows with your child! As the foundation of the Maxtrix System, it’s designed to adapt. When your toddler is ready for the next stage, simply remove the guardrails and raise the bed into a loft or bunk. No need to start over!

 

Tent Beds

Does your kid love to play? Add a cute tent to create a play area right in their bed! Our top tents are always the same height, at 20.75 inches tall. These playful additions create a comfortable sleeping space that blocks out sound and light, wrapping them in a cozy haven. The best part is our tents can easily be added onto any Maxtrix bed, and removed when your kid gets older!

Kindergarten through 3rd Grade (Ages 5 - 9 years old)

Ready to go higher? As your child moves from preschool into kindergarten, it’s the perfect time for their bed to grow right along with them! But not just any bed will do; it’s still important to choose a design with a low height and sturdy guardrails to keep safety top of mind.

Low Loft Beds

A low loft bed is very popular for elementary schoolers, and for good reason! Kids who are confident climbers love the elevated design, while parents appreciate that it’s high enough to be exciting but still low enough for peace of mind.

Maxtrix low loft beds for kids measure 50.75 inches from the floor to the very top of the bed, allowing 33.5 inches in under-bed height (measured floor to the bottom of the slats). These beds are perfect for kids measuring 40 inches or taller. 

While most kids won’t be able to stand beneath a low-profile loft, the space easily accommodates the sitting height of an average elementary schooler. The top step of the straight ladder is just 30" off the ground, making it easy to reach for children around 40" tall.

The sleeping surface (assuming a 5-inch mattress) is a total height of 38.75 inches off the ground. You can get this bed with 3 different entries – a straight ladder, an angled ladder, or a staircase. If your child may need a little extra help getting into their elevated bed, we recommend choosing a low loft bed with stairs, as it gives kids the easiest pathway to their bed.

 

Mid Loft Beds

A mid loft bed is a smart choice for taller kids, measuring 61.5" in total height with 44.25" of clearance underneath. Best suited for children 50" and taller, this style creates valuable space in smaller rooms, perfect for extra storage or play. Many parents love using the under-bed area to help organize toys and belongings, making the Mid Loft an ideal option for growing elementary schoolers.

 

Low Bunk Beds

For shared room or endless sleepover possibilities, low bunk beds are fun and safe for young kids. 

The top bunk for our low-profile bunk bed measures 45 inches to the top of the top bunk slat roll. Add to that the mattress thickness of 5 inches, and you have a sleeping surface height of 50 inches off the ground for the top bunk. For rooms with 8-foot ceilings, that leaves 46 inches of room for sleeping and sitting up.

Under-bed height measures 32.25 inches to the top of the slat roll, so if you add a 5-inch mattress, you are left with 27.25 inches of headroom between top and lower bunk. Maxtrix low bunk beds are a perfect solution for rooms with lower ceilings, giving kids the fun of a bunk without sacrificing comfort or safety.

 

Medium Bunk Beds

Our medium bunk beds are one step up from our low bunks. The increase in height provides more headspace and the option for underbed storage or a trundle. 

The top bunk for our medium bunk measures 50 inches to the top of the top bunk slat roll. Add to that the mattress thickness of 5 inches, and you have a sleeping surface height of 55 inches off the ground for the top bunk. For rooms with 8-foot ceilings, that leaves 41 inches of room for sleeping and sitting up.

Under-bed height measures 37 inches to the top of the slat roll, so if you add a 5-inch mattress, you are left with 32 inches of headroom. Explore all our medium bunk beds for the perfect in-between bunk bed height!

4th Grade through Middle School (Ages 9 - 12 years old)

Transitioning to middle school means more homework, busier schedules, and, most importantly, growth spurts. It’s the perfect time to upgrade to a larger bed and a design that balances comfort, study space, and storage to support every part of their day.

Luckily, with the Maxtrix System, beds grow right alongside your child. When growth spurts happen, you don’t have to start over, any Maxtrix bed can adapt to fit their changing needs and size.

 

High Loft Beds

High loft beds are popular choices for kids 50" and taller, offering plenty of room to grow. With 52.5" of under-bed clearance, high lofts are ideal if you’d like to add a desk or create a lounge area (see our Storage & Desk Fit Guide for details).

Ceiling height is also important to consider, these beds work best in rooms with 8-foot ceilings or higher. To maximize headroom on the top bunk, we recommend pairing with a low-profile 5" mattress.

A high loft bed frame measures 54" from the floor to the top of the slat base. With a 5" mattress, the sleeping surface sits at 59" off the ground. In a room with 8-foot ceilings, that leaves about 37" of headroom for sleeping and sitting up. Be sure to check your child’s sitting height to confirm there’s enough clearance, and choose the right mattress height to maximize comfort.

 

7th Grade and Beyond (Ages 12 & Up)

Maxtrix beds are designed to last from elementary school through college. By the time your child reaches high school, their room becomes so much more than a place to sleep. It’s a late-night study spot, a hangout space with friends, and their own private retreat. With the right bed setup, you can create a design that supports every part of their life.

Uber High Loft

Looking to maximize the amount of space under your loft bed? Then an uber loft bed is the perfect choice! Ideal for teens and kids 12 and up, this loft bed offers plenty of room to create a study bed space or gaming spot underneath while opening up your room for other furniture. It's even tall enough for most adults to stand comfortably underneath.

When shopping for an uber loft bed, it's also important to consider the ceiling height in your room. With its extra-tall height, this type of high loft bed requires at least 97.86 inches between the floor and ceiling for assembly.

 With a kids’ loft bed this high, we've made safety an extra priority. Two cross bars on three sides offer additional stability, while our industry-leading 16-inch guardrails provide unmatched sleep security. 

Tall Bunk Beds

Our Tall Bunk Beds are ideal for older siblings sharing a room, offering plenty of personal space for each teen. They’re also a favorite for sleepovers and hangout time with friends.

The top bunk for our tall bunk beds measures 54.5 inches to the top of the top bunk slat roll. Add to that the mattress thickness of 5 inches, and you have a sleeping surface height of 59.5 inches off the ground for the top bunk. For rooms with 8-foot ceilings, that leaves 36.5 inches of room for sleeping and sitting up. Under-bed height measures 41.75 inches to the top of the slat roll, so if you add a 5-inch mattress, you are left with 36.75 inches of headroom. 

Make Your Bed Size Selection

With these dimensions in mind, you can choose the best bunk bed, loft, or kids’ bed to fit your child’s needs. With Maxtrix, your bed can change over time, and you’re never locked into one setup.

Think of Maxtrix's modular system like a set of Lego bricks; you can build and rebuild your perfect bed setup all the way from toddler to college. Kids love the flexibility as their room adapts to their needs, and parents love that they don’t have to purchase a new bed every few years. 

Still have questions or want personalized guidance? Our design team is here to help, just reach out through our online chat or contact us directly!

Explore the endless possibilities of The Maxtrix System for a setup that works today and for years to come! 

FAQ: 

What is the size of a child's bed?

Children’s beds come in several sizes, but the most common starting point is a twin bed (38" x 75"). Some families choose a toddler bed first, while others go straight to a twin or even a full, depending on their child’s age, size, and room space.

Is a youth bed the same size as a twin bed?

No, a youth or toddler bed is different than a twin-size bed. A youth bed is typically smaller and lower to the ground than a standard twin, often designed as a transitional step from a crib to a bed. 

At what age should my child get a full-size bed? 

Many parents move their kids into a full-size bed around ages 9–12, especially during growth spurts or when they want extra sleep space. Full-size beds can work for younger children too, but it’s best to add guardrails and ensure they can safely climb in and out on their own.