5 Little Monkeys Kids Mattress — 4 Years Old
About the 5 Little Monkeys Mattress
5 Little Monkeys is a company that makes mattresses specifically designed for children. While most kids end up sleeping on whatever hand-me-down mattress is available, 5 Little Monkeys argues that kids deserve a mattress designed for their bodies — lighter weight, different sleep positions, and growing bones.
At around $500-700 for a Twin, it's more expensive than a basic kids mattress from a big box store. But it's also designed to last from age 3 to 18, potentially replacing multiple cheaper mattresses over that span.
I wanted to see what's actually inside this kids mattress and whether the construction justifies the price for parents who are considering it.
Measuring the Mattress
Measuring the mattress height
The 5 Little Monkeys mattress is 8 inches tall — shorter than most adult mattresses (typically 10-14 inches). This is intentional for a few reasons:
- Fits standard bunk beds and trundles without being too tall
- Easier for smaller kids to climb in and out of bed
- Lower profile means less risk of injury if a child rolls off
The mattress measures as advertised at 8 inches. The Twin dimensions are standard (39" x 75"), so it fits regular Twin frames, bunk beds, and daybeds. The shorter height makes sense for kids — my own kids had an easier time with it than with taller mattresses.
Testing with Actual Kids
Let's be honest — kids don't just sleep on their mattresses. They jump on them, stand on them, roll around, and generally put them through more abuse than adults do. A kids mattress needs to handle this.
The mattress handled the jumping test well. The foam bounced back without any permanent indentations from the jumping/standing. This is important because cheap foam would compress and not recover. The 5 Little Monkeys foam density seems appropriate for handling kid abuse while still being comfortable. At 4 years old, this particular mattress was showing some wear in the main sleep area — the comfort foam was softer there than at the edges. Normal for the age, but it suggests kids mattresses wear just like adult ones.
The Foam Feel
5 Little Monkeys uses what they call "responsive memory foam" — it's memory foam, but formulated to be more responsive (bounce back faster) than traditional memory foam. This makes sense for kids who move around a lot in their sleep.
The foam has that classic memory foam feel where you can see your handprint, but it bounces back faster than traditional slow-response memory foam. This is good for active sleepers because they won't feel "stuck" in the foam. The cooling gel in the top layer helps prevent that hot feeling memory foam is known for.
Inside: The 3-Layer Construction
The 5 Little Monkeys mattress cut open, showing all 3 foam layers
Here's what's inside the 5 Little Monkeys mattress:
Layer 1: Cooling Comfort Foam
The top layer features Dual Phase Change gel with an open cell structure. Phase Change Material (PCM) absorbs heat when your body warms up and releases it when you cool down — this helps regulate temperature throughout the night. The open cell structure allows for better airflow.
Layer 2: Responsive Memory Foam
The middle layer is responsive memory foam designed to provide support and pressure relief for lighter-weight bodies. This layer is what gives the mattress its contouring feel while still providing pushback so kids don't sink in too deep.
Layer 3: High-Density Support Base
The bottom layer is dense support foam that provides the structural foundation for the mattress. This is what determines how long the mattress will last — a dense base prevents the mattress from bottoming out and maintains its shape over time.
The total comfort layer is about 3 inches, with the remaining 5 inches being support foam. This ratio makes sense for kids — they don't need as much cushioning as adults because they weigh less. All three foam layers are CertiPUR-US certified, meaning they meet standards for low emissions and no harmful chemicals. The foam density feels appropriate for the intended use — not as dense as an adult mattress, but dense enough to last. The downside: because the foam is calibrated for lighter bodies, an older teen (or an adult sitting on the bed) will bottom out faster than on an adult mattress. This is by design, but keep it in mind if your kid is already teenage-sized.
Fiberglass Check
5 Little Monkeys does not use fiberglass in their mattresses. This is particularly important for a kids mattress — you don't want fiberglass anywhere near where children sleep.
No Fiberglass
5 Little Monkeys mattresses do not contain fiberglass.
The cover is made from OEKO-TEX certified organic cotton, which means it's been tested for harmful substances. Combined with the CertiPUR-US certified foam, this is a mattress you can feel good about putting in your kid's room.
Safety Certifications
For a kids mattress, certifications matter even more than for adult mattresses. Kids are more sensitive to chemicals, and they spend more time in direct contact with their mattress (playing, reading, etc.).
- CertiPUR-US — All foam is tested for harmful chemicals, low emissions, and no ozone depleters, formaldehyde, heavy metals, or phthalates
- OEKO-TEX — The organic cotton cover is tested for harmful substances
- No Fiberglass — Uses alternative fire barriers
The certifications are legitimate — I checked the tags and verified them. For a kids mattress, this level of certification is exactly what you want. There's no concerning smell or off-gassing, which matters when you're putting this in your child's bedroom.
Who This Mattress Is For
Good For
- Children ages 3-18
- Parents concerned about mattress chemicals
- Bunk beds, trundles, and daybeds (8" height)
- Kids who move around a lot in their sleep
- Parents who want one mattress to last through childhood
- Families with kids who have allergies or sensitivities
Probably Not For
- Adults (designed for lighter bodies)
- Budget shoppers (cheaper kids mattresses exist)
- Kids under 3 (should be on crib/toddler mattress)
- Heavier teens who need more support
Is It Worth the Price?
At $500-700 for a Twin, the 5 Little Monkeys is more expensive than budget kids mattresses ($100-200). Here's how I think about the value:
- Designed to last 15 years — From age 3 to 18, you'd potentially buy 2-3 cheap mattresses in that time
- Better materials — CertiPUR-US foam and OEKO-TEX cotton vs. unknown materials in budget options
- No fiberglass — Many budget mattresses use fiberglass fire barriers
- Designed for kids — Foam density appropriate for lighter bodies, not just a smaller adult mattress
If you buy a $150 mattress and replace it every 5 years, you've spent $450 over 15 years — close to the 5 Little Monkeys price. The difference is the quality of materials your kid sleeps on during that time.
My Take
I've torn apart hundreds of kids mattresses over the years, and most of them are junk — cheap foam, questionable materials, and sometimes fiberglass fire barriers that can be a nightmare if they leak out. The 5 Little Monkeys is legitimately better than most.
The construction is solid for a kids mattress. The foam density is appropriate — not too soft that a kid will sink in, not too firm for their lighter bodies. The certifications are real, and there's no fiberglass to worry about.
Is it worth $500-700? If you care about what materials your kid sleeps on and want something that will last through their childhood, yes. If you just need something functional and will replace it in a few years anyway, there are cheaper options.
For parents who want a quality kids mattress with real certifications and no fiberglass, the 5 Little Monkeys is one of the better options in the market. It's designed specifically for kids rather than just being a smaller adult mattress.
Check Current Pricing
See current prices and any available bundles on 5 Little Monkeys' site.
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