Cot Mattress Size Guide, Australia

The standard cot mattress size in Australia is approximately 130 × 69 cm, sized to fit a standard household cot with an internal frame of about 132 × 71 cm. Portacot and travel cot mattresses are smaller (typically 91 × 65 cm), and bassinet mattresses vary widely but usually fall between 78 × 40 cm and 92 × 50 cm. The critical safety rule: the mattress must fit snugly with no more than a 2 cm gap on any side, per the Australian voluntary cot safety standard AS/NZS 2172:2013. Below we cover standard sizes, how to measure your specific cot, cot vs bassinet vs portacot sizing, and safe-fit guidance.

Key Takeaways

• The standard cot mattress size in Australia is approximately 130 × 69 cm, designed to fit a standard household cot

• Portacot and travel cot mattresses are typically 91 × 65 cm; bassinet mattresses vary widely from 78 × 40 cm to 92 × 50 cm and are usually custom to the bassinet model

• The Australian voluntary cot safety standard (AS/NZS 2172:2013) specifies no more than a 2 cm gap between the cot mattress and the cot frame on any side

• Always measure your specific cot's internal dimensions before buying a mattress; nominal sizes vary between manufacturers

• Cot mattresses should be firm (not soft) per Red Nose Australia guidance to reduce SIDS risk; consult Red Nose Australia and the ACCC Product Safety guidance for authoritative recommendations

Standard Cot Mattress Sizes in Australia

Cot mattress sizing in Australia falls into four broad categories: standard cot, compact or mini cot, portacot and travel cot, and bassinet. Nominal sizes vary between manufacturers by 1 to 2 cm, so always confirm the exact size against your specific cot before purchase.

Standard cot is the most common purchase in Australia. Compact cot suits smaller nurseries or homes with less floor space. Portacot mattresses ship with the portacot itself, so replacement should use the portacot manufacturer's recommended replacement size. Bassinet mattresses are highly bassinet-specific because bassinet shapes vary.

How to Measure a Cot Mattress Before You Buy

Measure a cot mattress in three steps: measure the internal dimensions of your cot frame, calculate the gap that a candidate mattress would leave on each side, and confirm the mattress depth clears the top rail with adequate safety margin. Do this before you buy the mattress, not after it arrives.

Step 1, Measure the Inside of the Cot Frame

Use a tape measure and record the internal length and width of the cot frame at the level where the mattress will sit (some cots have adjustable base heights, so start at the lowest setting). Measure at multiple points along each side because some cot frames are slightly wider at the base than at the top rail. Record measurements in centimetres. The mattress you buy should match these internal dimensions minus about 1 to 2 cm total, so a 132 × 71 cm internal frame typically calls for a mattress of about 130 × 69 cm.

Step 2, Check for Gaps Around the Edges

Once you have the cot's internal dimensions, calculate the gap a candidate mattress would leave on each side: subtract the mattress dimensions from the cot dimensions and divide by 2 (for each side). The gap should be no more than 2 cm on any side, per the Australian voluntary safety standard AS/NZS 2172:2013. A gap over 2 cm is a strangulation and entrapment risk; a gap under 1 cm is ideal for a snug, safe fit that still allows the mattress to be lifted for cleaning.

Step 3, Confirm the Depth Clearance

Check the mattress depth (thickness) against your cot's mattress base settings. Most standard cot mattresses are 8 to 15 cm deep. When the cot base is at its lowest setting (used once your baby can pull to stand), the cot's top rail should sit at least 30 cm above the mattress surface to prevent your baby climbing out. Confirm your cot manufacturer's recommended mattress depth before purchase.

Cot Mattress vs Bassinet & Portacot Sizes

A cot mattress is typically 130 × 69 cm for a standard AU cot; bassinet mattresses are much smaller (78 × 40 cm to 92 × 50 cm) and shaped for newborn use in bassinet frames; portacot mattresses are typically 91 × 65 cm for travel or occasional overnight stays. Each is sized for its specific bed frame, and mattresses aren't interchangeable across the three uses.

Key sizing differences:

• Cot mattress (~130 × 69 cm): standard household cot, main sleep space from newborn to toddler

• Bassinet mattress (78 × 40 cm to 92 × 50 cm): newborn use in a bassinet frame, typically for the first 3 to 6 months

• Portacot mattress (~91 × 65 cm): travel and occasional overnight, portacot frames are lightweight and foldable

• Compact/mini cot mattress (~120 × 60 cm): smaller nursery footprint, less common but growing in popularity for compact urban homes

Mattresses shouldn't be swapped between these formats. Using a bassinet mattress in a cot leaves gaps far exceeding the 2 cm safety limit; using a cot mattress in a portacot won't physically fit. Buy the correct mattress for the specific frame you have.

Choosing the Right Fit for Safety

The Australian voluntary safety standard AS/NZS 2172:2013 specifies that a cot mattress should fit snugly with no more than a 2 cm gap on any side of the cot frame. Red Nose Australia recommends firm cot mattresses (not soft) to reduce SIDS risk. Always confirm both the fit standard and the firmness recommendation before purchasing.

Key safety points to check:

• Fit gap (AS/NZS 2172:2013): no more than 2 cm between the mattress and the cot on any side

• Firmness (Red Nose Australia guidance): firm mattress, not soft, to reduce SIDS risk

• Cot mandatory standard: the cot itself must meet the mandatory AS/NZS 2172:2013 household cots standard for sale in Australia

• No pillows, quilts or soft bedding in the cot with infants under 12 months (per Red Nose Australia)

• Second-hand cot mattresses: Red Nose Australia recommends against using second-hand cot mattresses due to hygiene and integrity concerns

• Mattress protector: a firm, breathable mattress protector helps with cleaning without compromising the firm-fit safety standard

For authoritative safety guidance, consult Red Nose Australia and the ACCC Product Safety guidance on cots and cot mattresses before purchase. These are the authoritative Australian sources for infant sleep safety.

Explore Our Kids Sleep Range for the Move from Cot to Bed

Our current Koala kids range is designed for the transition from cot to single-size bed, when children move out of the cot into their first "big kid" bed (typically between 2 and 3 years of age). Our range includes single-size kids mattresses, bed bases, and a guardrail for the transition period, all backed by our 120-night trial and 10-year warranty. Explore:

• Koala Joey Kids Mattress: our kids mattress for children moving from cot to single-size bed.

• Koala Snoozytime Mattress: our premium kids mattress option.

• Koala Joey Bed Base: timber bed base designed for kids' single-size beds.

• Koala Snoozytime Bed Base: premium kids' bed base.

• Koala Joey Guardrail: safety guardrail for children transitioning from cot to their first single bed.

A note on cot mattresses. Our current Koala Kids range is designed for children who have transitioned out of a cot into a single-size bed, rather than for cot use itself. If you're specifically looking for a cot mattress, refer to your cot manufacturer's recommended replacement size, follow the Australian voluntary safety standard AS/NZS 2172:2013 for the 2 cm fit gap, and consult Red Nose Australia for firmness guidance.