Cot dimensions and mattresses: which size is right?
In France, two sizes account for most beds for young children: the compact, classic 60x120 cm and the 70x140 cm, designed to last as your child grows. The rule of thumb is always the same: measure the inside of the cot, between the bars, and choose a mattress that fits snugly, with no gaps at the sides. This helps ensure comfort and safety.
What size mattress does a baby cot need?
Mattress size is determined by the cot's internal dimensions, not the outer frame. This measurement, taken between the bars, determines the right size.
- The 60x120 cm size is the classic, more compact cot, designed for little ones from birth.
- The 70x140 cm size is used for convertible cots: twenty extra centimetres in length to accommodate a growing child without having to replace the bed too soon.
In both cases, a well-fitting mattress remains the foundation of a safe sleeping space. For the very first days, some parents choose a carrycot or cradle, whose smaller size offers a reassuring, cocoon-like space before moving on to a cot, then a junior or convertible bed. At Charlie Crane, we design furniture made to stand the test of time, favouring natural materials such as European wood to create a sleep space that is both healthy and durable.
Baby carrycot dimensions
During the very first months, a carrycot or cradle often provides a place for your baby to sleep before they move into a cot with bars. Unlike a standard baby cot, carrycots do not come in a single size: common dimensions are around 40x80 cm, sometimes 40x90 cm or 45x90 cm depending on the model. It is therefore important to check the exact size before choosing a matching mattress.
The main benefit of this compact size is its cocooning effect: a snug space reminiscent of the enclosed feeling of the final months of pregnancy, which may help your baby settle to sleep more peacefully. Lightweight and often fitted with handles, a carrycot is easy to move from room to room.
As for safety, the same principles apply as for a cot: a firm mattress that fits perfectly, with no gaps at the sides. This stage is short-lived: as soon as your baby starts rolling over or becomes more mobile, it is time for a roomier, convertible cot with bars.
Why must a mattress fit a baby cot properly?
A properly fitting mattress is not just a matter of comfort: it is an important safety issue. If there is a gap between the mattress and the bars, a child's arm or head could slip into it and become trapped. Manufacturers address this risk by matching mattress dimensions to cot dimensions, whether 60x120 or 70x140 cm.
A simple check will tell you whether it fits:
- slide your hand between the mattress and the frame on all four sides;
- if it slips in easily, the mattress is not suited to the size of the cot;
- a correctly sized mattress supports a child's body evenly, for more restful sleep.
That is also why, at Charlie Crane, we favour natural, breathable materials: your baby's wellbeing begins with a sleeping space that fits them just right. For families planning ahead, the baby cot collection makes it easier to prepare for the move to a junior bed without compromising on style or comfort.
NF EN 716 baby mattress safety standards
The NF EN 716 standard governs the manufacture of all cots with bars sold in France, whether 60x120 or 70x140 cm. It requires spacing between the bars of 4.5 to 6.5 cm, so that a child's head or arm cannot become trapped, as well as a minimum height between the mattress and the top of the bars to reduce the risk of falls. These requirements apply whichever size you choose.
For families, the simplest guide is the manufacturer's label: it should state that the cot complies with this standard. At Charlie Crane, safety is an integral part of the design: a well-built cot made from European wood, paired with a perfectly fitting mattress, lays the foundation for restful sleep for children and peace of mind for parents.
New baby mattress standards for 2026
No major regulatory overhaul has changed the existing framework: the NF EN 716 standard remains the reference for 60x120 cm and 70x140 cm sizes. What is changing is how people choose and use them: there is growing attention to how precisely the mattress fits the cot, a key safety criterion when buying.
Families are also paying closer attention to what mattresses are made of: organic cotton, natural fibres and breathable materials are gaining ground over conventional synthetic foams, driven by demand for transparency about where materials come from. In terms of size, the 70x140 cm option is appealing to more households keen to avoid repeated purchases. But no trend replaces the essential check: measure the inside of the cot and choose a mattress that fits precisely, with no gaps around the edges.
What are the standard dimensions of a baby cot?
In France, two baby cot sizes set the standard across the market:
| Size | Approximate period of use | Key feature |
|---|---|---|
| 60x120 cm | from birth to around 2-3 years, depending on the child's build | ideal for small bedrooms and shared spaces |
| 70x140 cm | for longer, with the option to convert it into a junior bed using a low guard rail | twenty extra centimetres in length |
One essential point: the stated dimensions refer to the cot’s internal sleeping area, not the external measurements of its frame. This internal measurement should guide your choice of baby mattress. Other sizes are available, such as carrycots and cradles for the very first months, but they are less common and offer a more limited choice of accessories.
For a nursery designed to last, frames made from European wood, solid pine or beech depending on the model, provide the strength needed to see your child through each stage of growth. That is the idea behind furniture made to last: a sturdy bed base, natural materials and a size suited to each stage of your child's sleep.
Frequently asked questions
What is the difference between a 60x120 and a 70x140 cm baby cot? The 60x120 cm size is the traditional compact option, designed for the early years. The 70x140 cm size offers twenty extra centimetres in length and lasts longer as your child grows, with the option to convert it into a junior bed.
How do you choose the right mattress size for a baby cot? Measure the inside of the cot, between the bars, and choose a mattress with matching dimensions and no gaps at the sides. This ensures a safe place to sleep.
Which standard governs cot safety in France? The NF EN 716 standard specifies, among other things, the spacing between the bars and the minimum height between the mattress and the top of the cot, to reduce the risks of entrapment and falls.
When should a baby move from a carrycot to a cot with bars? As soon as your baby starts rolling over independently or becomes more mobile, a roomier cot with bars is preferable to a carrycot.
Should there be a gap between the mattress and the cot? No: a properly fitting mattress should leave no gaps at the sides, to prevent a child from becoming trapped.
