Cot Bed Sheet Sizes Explained: Will 140 x 70cm Fit?

Quick answer

A 140 x 70cm sheet is the standard cot bed size, so it fits most cot beds and toddler beds that use a 140 x 70cm mattress. It will not fit a standard cot (usually 120 x 60cm) or a travel cot (often around 95 x 65cm). Measure your mattress length and width before buying, and check the depth if your mattress is unusually thick.

What 140 x 70cm actually fits

140 x 70cm is the common cot bed mattress size in the UK and Ireland. Cot beds are designed to convert from a cot into a toddler bed, so the mattress stays the same size while the side rails come off. If your mattress measures 140cm long and 70cm wide, a 140 x 70cm fitted sheet is the correct size.

The sheet needs to cover the full sleeping surface and tuck under the mattress. A fitted sheet with an elasticated hem is the practical choice because it stays put when your child moves around, and it comes off quickly for middle-of-the-night changes.

Cot bed vs cot mattress size: the difference that matters

A standard cot mattress is usually 120 x 60cm, while a cot bed mattress is usually 140 x 70cm. That 20cm difference in length and 10cm in width is enough that a cot sheet will not stretch onto a cot bed mattress, and a cot bed sheet will bunch on a cot.

If you are buying for a cot, look for sheets labelled for a 120 x 60cm mattress. If you are buying for a cot bed, look for 140 x 70cm. Some retailers use the terms interchangeably, so the measurement on the label is more reliable than the product name.

Will a cot bed sheet fit a travel cot?

Usually no. Travel cot mattresses are often around 95 x 65cm, and some are smaller or a different shape. A 140 x 70cm sheet will be far too long and will bunch under your baby, which is a safety concern because loose fabric can cover the face.

If you need a sheet for a travel cot, measure the travel cot mattress itself and buy a sheet made for that measurement. If you cannot find one, a fitted sheet that is slightly too small is safer than one that is too large, but the best option is a sheet sized for the travel cot.

How to measure your cot mattress in two minutes

Take the mattress out of the cot and lay it flat. Measure the length from end to end at the longest point, then the width at the widest point. Measure the depth too, from the top surface to the bottom edge, because a deep mattress needs a sheet with enough stretch to reach under it.

Write the three numbers down and compare them with the sheet's stated size. If your mattress is 140 x 70cm and up to about 10cm deep, a standard 140 x 70cm fitted cot bed sheet should work. If it is much deeper, check the sheet's description for depth guidance or choose a sheet with a generous elasticated hem.

Fabric and fit: what to look for in a cot bed sheet

Cotton muslin is a popular choice for cot sheets because it is soft, breathable and lightweight. Breathable fabric helps regulate body temperature, which matters because overheating is a risk factor for safe sleep. Muslin also feels gentle against delicate skin and washes well.

Look for a stretchy elasticated hem. It keeps the sheet secure on the mattress and makes bed changes faster. A sheet that fits properly lies flat with no wrinkles or loose folds, so there is nothing for small hands to pull up.

Decision rules for buying a cot bed sheet

• If your mattress measures 140 x 70cm: Buy a 140 x 70cm fitted cot bed sheet. Check the depth if your mattress is thicker than about 10cm. This is the standard cot bed size and the most common sheet size.
• If your mattress measures 120 x 60cm: Buy a cot sheet, not a cot bed sheet. A 140 x 70cm sheet will be too loose. Loose fabric is a safety risk, so match the sheet to the mattress.
• If you are buying for a travel cot: Measure the travel cot mattress and buy a sheet made for that size. Most travel cots are not 140 x 70cm. Do not size up. A snug fit matters more than a generous one.
• If you want a breathable sheet for temperature regulation: Choose cotton muslin with an elasticated hem. It is soft, lightweight and helps regulate body temperature. Muslin is a good choice for most nurseries, especially in warmer months.

Cot bed sheets that fit 140 x 70cm

• Cotton Muslin Fitted Cot Bed Sheet 140 x 70cm - Goose & the Ladybird: 100% cotton muslin fitted cot sheet in 140 x 70cm, with a stretchy elasticated hem for a secure fit and quick bed changes. The breathable muslin helps regulate body temperature, and the elasticated hem keeps the sheet flat on the mattress.
• Cotton Muslin Fitted Cot Bed Sheet 140 x 70cm - Sweet Safari: 100% cotton muslin fitted cot sheet in 140 x 70cm, soft, breathable and lightweight, with a stretchy elasticated hem. A practical everyday option if you want a second sheet for wash days without changing the fit.
• Frill Muslin Blanket - Bunnies: Cotton muslin blanket with a decorative frill edge, layered for extra cosiness and suitable for the pram or nursery. Useful for pram walks or as a light layer, but not a substitute for a fitted cot sheet.

Who this size is for

Best for

• Cot beds and toddler beds with a 140 x 70cm mattress
• Parents who want a breathable cotton muslin sheet with a secure elasticated hem
• Anyone replacing a worn or stained sheet and wanting a like-for-like fit

Not for

• Standard cots with a 120 x 60cm mattress
• Travel cots, which usually need a smaller sheet
• Moses baskets or bedside cribs, which use different sizes