A deep fitted bed sheet is a fitted sheet designed to accommodate deeper mattresses and regular mattresses used with a topper. A deep fitted sheet is 40cm deep; 10cm deeper than a regular fitted sheet. This extra depth means you can be sure your fitted sheet will be easy to put onto your mattress and will stay in place securely. Using a deep fitted bed sheet with a topper lets you fully benefit from the topper's extra cushioning and support - using a regular depth fitted sheet can 'squash' the fill in your topper, making it less effective. 

Not sure whether you need a deep fitted bed sheet or a regular bed sheet? Deep fitted bedsheets have a depth of 40cm, while regular fitted sheets have a depth of 30cm. We'd suggest you measure the combined depth of your mattress and - if you have one - your mattress topper. If the depth of your mattress and topper measures in at 30cm or less, a regular fitted sheet is perfect. If it's over 30cm, you will need a deep fitted sheet.

This depends on the type of mattress topper you have and the depth of your original mattress. Some mattress toppers are very deep, while others, such as our New Zealand Wool topper, are more slimline. To be sure, we'd recommend you measure the combined depth of your mattress and mattress topper. If the depth of your mattress and topper measures 30cm or less, a regular fitted sheet is perfect. If it's over 30cm, you will need a deep fitted sheet. If you are buying a new mattress or topper, check the measurements in the 'technical information' section of the product you are buying, or take a look at our size guide.