One adds comfort, the other adds protection
This is the most common mix-up in bedding. A mattress topper is a thick padded layer you put on top of the mattress to change how the bed feels. A mattress protector is a thin washable cover fitted over the mattress to keep it clean. They sit in almost the same place, but they solve completely different problems.
Mattress topper at a glance
- Typically 5–10 cm deep, filled with microfibre or foam.
- Changes the feel of the bed: softer, more cushioned, better supported.
- Helps revive an older mattress that has lost some of its comfort.
- Held in place by deep elasticated corner straps.
- Offers no meaningful defence against spills.
Mattress protector at a glance
- Only a few millimetres thick and fitted like a bottom sheet.
- Barely changes the feel of the bed at all.
- Keeps moisture, dust and allergens out of the mattress.
- Comes off and washes easily, as often as your sheets.
- Available quilted for a little softness, or waterproof for spill defence.
Do I need both?
Plenty of people use both, and they layer neatly. Mattress first, then a protector, then the topper, then a second protector over the topper if you want to keep that clean too, and finally your sheet. If you are only buying one, ask whether your complaint is about comfort or about cleanliness. That answer tells you which product you need.
Matching the sizes
Both come in the same UK bed sizes, so you can pair them exactly: Single 90 x 190 cm, Small Double 120 x 190 cm, Double 135 x 190 cm, King 150 x 200 cm and Super King 180 x 200 cm. With a protector, also check the skirt depth against the height of your mattress, and add the depth of the topper if the protector is going over the top of it.
A quick rule of thumb
If the bed feels wrong, buy a topper. If the bed feels fine and you want it to stay that way, buy a protector.
