Mattress Sizes for Growing Families: A Comprehensive Guide

As your family grows, so do your needs—including the all-important quest for the perfect mattress.

From toddlers making their big-kid bed debut to teens who suddenly need more legroom, choosing the right mattress size can make a world of difference in getting a good night’s sleep.

And let’s be real—anything that helps kids sleep better is a huge win for parents, too. So, we’re breaking down what type of mattress is best for kids and teens, with handy tips to make the transition smoother (and hopefully bedtime battles a thing of the past).

Toddler Bed Mattress: A Small Step into Big Dreams

The cot-to-bed transition is a major milestone—cue the proud tears! A toddler bed mattress, usually around 700 mm x 1400 mm, is the perfect next step, giving them a cosy space while still feeling safe and snug.

When shopping for your tiny dreamer, look for a firm yet comfy mattress to support their growing spine. According to the Sleep Health Foundation, toddlers need around 11-14 hours of sleep per day to support their rapid development so breathable materials may help keep them cool, and a waterproof cover? Absolute lifesaver.

Pro Tip: Many cot mattresses are dual-sided—one side for babies, one for toddlers. Flip it when they’re ready for an upgrade, and boom, instant big-kid bed without the extra cost.

Single Mattress for Kids: Room to Grow

One minute they’re tiny, the next they’re bouncing off the walls—literally. A single mattress (920 mm x 1880 mm) is the go-to for kids, offering enough room for wriggly sleepers while keeping their bedroom spacious for toys, desks, and general chaos.

Single mattresses are also a bunk bed’s best friend, making them perfect for siblings sharing a room. Or, if you’re feeling nostalgic for your own childhood sleepovers, place two single mattresses for kids side by side for late-night giggles, whispered secrets, and flashlight-under-the-covers storytelling.

When choosing what type of mattress is best for kids, think long-term: a medium-firm mattress supports their growth, while hybrid or memory foam styles may be a good option for kids who need extra cushioning or support. Many experts recommend that kids aged 6-12 get around 9-12 hours of sleep to help support healthy growth and development. Choosing a mattress that offers the right support is essential for helping them rest and recharge. 

Pro Tip: Short on space? Bunk beds with single mattresses are a game-changer—more floor space for playtime, though there may be some fighting over who gets the top bunk! 

Best Mattress for Teens: Extra Space for Growing Needs

Teenagers: one day they’re curling up in their single bed, the next they’re stretching out like starfish and complaining about "not enough room." If your teen is outgrowing their sleep space faster than their wardrobe, a long single mattress (920 mm x 2030 mm) or king single mattress (1070 mm x 2030 mm) could be the answer.

The best mattress for a teenager depends on their sleep style. Side sleepers? Go for plush cushioning. Back or stomach sleepers? A firmer option will keep them supported. A hybrid mattress is a solid all-rounder—perfect for teens juggling school, sports, and screen time.

Pro Tip: As teens tend to stay up late, encourage a sleep-friendly environment by investing in a supportive mattress that helps them recharge fully.

Upgrading to Larger Sizes: Double or Queen Beds

If your teen is dreaming of more space, a double mattress (1370 mm x 1880 mm) or queen mattress (1530 mm x 2030 mm) could be the ultimate sleep upgrade. These sizes offer room to stretch out and last well into adulthood, making them a smart investment.

Double and queen mattresses are also a great solution for teenagers who toss and turn (we see you, restless sleepers). Plus, if your teen’s room has the space, upgrading now means you won’t need to do it again in a few years. Win-win!

Pro Tip: If you’re considering a larger mattress, invest in quality bed linen and pillows designed for growing teens. The right sleep accessories can enhance comfort and sleep quality.

Mattress Considerations for Shared Rooms

Sharing a room doesn’t have to mean compromising on comfort. Bunk beds and trundles can work wonders, giving each child their own sleep space while keeping the room tidy.

When picking a bunk bed mattress, ensure it fits snugly and offers good support. Single or king single mattresses are ideal for bunk setups—just make sure the top bunk has a lower-profile mattress for safety.

Pro Tip: A trundle bed under a bunk or single bed can provide a handy extra sleeping space for sleepovers or guests.

Tips for Choosing the Right Mattress for Kids and Teens

1. Prioritise Support: A growing spine needs proper alignment—opt for a supportive mattress that will ensure your child has a restful sleep.

2. Consider Room Size: Ensure the mattress fits comfortably in the room, leaving space for other furniture and activities.

3. Think Long-Term: Investing in a slightly larger mattress now can save you the hassle of upgrading as your child grows.

4. Test It Out: If possible, have your child or teen try out the mattress in-store to find what feels best for them.

5. Look for Hypoallergenic Materials: If your child suffers from allergies, choose a hypoallergenic mattress to promote better sleep and overall health.
   

A Mattress for Every Stage

Whether it’s a toddler taking their first leap into a big-kid bed or a teenager stretching out into a queen, Forty Winks has your family covered. With expert-backed support, space-saving solutions, and sleep-friendly materials, we’re here to make sure everyone gets the rest they need (yes, even you, sleep-deprived parent!).

No matter what stage your family is in, you’ll find the perfect mattress fit at Forty Winks. Click here to shop kids beds.