Sizes

Toddler and crib bedding sizes

Updated August 2026

The measurements here are simple and fixed. The harder question — whether a filled cover belongs in the bed at all yet — has a clear answer, and it is not a matter of taste or decorating preference.

Safety before sizing

The American Academy of Pediatrics recommends a bare crib for the first 12 months of life. That means a firm, flat mattress, a fitted sheet, and nothing else in the crib: no comforters, no quilts, no duvet covers, no pillows, no bumper pads, no loose blankets, no sleep positioners, no stuffed animals. Soft and loose bedding raises the risk of suffocation and re-breathing, and no amount of careful tucking makes it appropriate for an infant.

A wearable blanket — a sleep sack sized so the neck opening is smaller than the child's head — is the standard way to keep a baby warm without loose fabric. Room temperature does the rest.

Soft bedding becomes reasonable around the toddler-bed transition, roughly 18 months to 2 years, once the child has moved to a low bed they can get into and out of on their own. That is a range, not a birthday. The relevant signals are the bed change itself, plus the child being able to push bedding off their own face reliably.

Treat this page as sizing information only. Follow current AAP guidance over anything written here, and ask your pediatrician about your own child rather than working from a general chart.

Exact dimensions

Crib mattresses are standardized in the United States, which makes this the least ambiguous size on the site. A standard toddler bed uses the same mattress as the crib — the frame changes, the mattress does not.

Drop math for a toddler bed

Drop per side is the cover width minus the mattress width, divided by two, minus the mattress height. A 40″ toddler cover on a 28″ mattress gives (40 − 28) ÷ 2 = 6″ per side. With a 5″ crib mattress, the cover reaches the bottom edge of the mattress and stops there.

That is the point. On a toddler bed the correct amount of overhang is barely any. You want the cover to end at or above the mattress base so nothing hangs into the floor space a small child steps into at 6 a.m.

Contrast that with the twin cover people reach for because it is cheaper and easier to find: a 68 × 90″ twin cover on the same 28″ mattress gives (68 − 28) ÷ 2 = 20″ per side. Subtract a 5″ mattress and roughly 14″ of fabric pools on the floor on each side, plus 38″ of extra length at the foot. It is a trip hazard and it drags the cover through everything on the floor between washes. Save the twin sizing for the twin bed, where our twin cover sizing applies properly.

Snug-fit rules and caveats

• The fitted sheet is the safety-critical piece. It must be sized for a 28 × 52″ mattress specifically. Pull each corner and let go — if it pops off, it is the wrong sheet, regardless of what the label says.
• No gap at the mattress edge. A crib mattress should sit tight against the frame on all four sides. Bedding cannot fix a loose mattress and should never be used to fill the gap.
• Thick mattresses change the math. Some toddler mattresses run 6″ rather than 4″. That eats the entire drop of a 40″ cover, so a 42″ cover suits deeper mattresses better.
• Skip the weighted blanket. Weighted bedding is not appropriate for infants or toddlers, whatever the size chart says.
• Buy two of everything washable. Toddler bedding gets stripped at 2 a.m. more often than adult bedding, and a spare set is what keeps that from becoming a crisis. Our notes on removing stains from bedding cover the specific ones you will meet.

What to buy, and what to check

Once soft bedding is appropriate, the two things worth spending attention on are fiber and finish. Plain woven cotton — percale in the 110–140 GSM range — breathes well, washes hot, and survives the wash cycle count that toddler bedding demands. Cotton jersey is softer and more forgiving of a rumpled bed, and holds up to weekly washing without ironing.

For chemical finishes, look for an OEKO-TEX Standard 100 label, and specifically Product Class I, which is the tier tested for articles used by babies and small children. It confirms the finished textile has been tested for harmful substances; it says nothing about organic farming or fabric quality, and it is not a safety rating for the bedding format itself. If you also want organic fiber, that is a separate claim — see organic cotton bedding for what GOTS certification actually covers.

For the covers themselves, our best kids' duvet covers roundup covers the ones built for hot washing and heavy rotation. When the twin bed arrives, the full size chart and the sizes hub handle the step up, and how often to wash bedding sets a realistic schedule.

FAQ

When can a child sleep with a comforter or quilt?

The American Academy of Pediatrics recommends a bare crib for the first 12 months, so soft bedding is not appropriate for an infant. It becomes reasonable around the toddler-bed transition, roughly 18 months to 2 years, once the child moves to a low bed they can get out of unaided. Follow current AAP guidance over any sizing chart.

Does a toddler bed use a different mattress than a crib?

No. A standard toddler bed takes the same 28 × 52″ crib mattress, which is why the frame change does not require new sheets. Only the top layers change.

Can I use a twin duvet cover on a toddler bed?

It fits in the sense that it covers the mattress, but a 68 × 90″ twin cover on a 28″ wide mattress drops 20″ per side and puddles about 14″ onto the floor. That is a trip hazard next to a low bed and it drags the cover through whatever is on the floor.

How often should toddler bedding be washed?

Sheets and covers weekly, and immediately after any illness or accident. Toddler bedding takes more spills than adult bedding, so a second set in rotation is genuinely useful rather than a luxury.