Mattress Topper Thickness: How Thick Should a Topper Be?
5 or 7 cm: what the height changes and what you can use as a guide when choosing.
Short answer: 5 or 7 cm?
For many beds, 5 to 7 cm is a common topper height: enough material to noticeably change how the bed feels, but not so much that bed and sheet cause problems. Thin layers of 2 to 4 cm feel more subtle, while toppers from 8 cm change the bed clearly and noticeably raise the entry height.
With 5 and 7 cm, our three models sit in exactly this range. Which height suits you depends on three things:
- How much change you want (subtle or clear).
- How high your bed already is and how easily you can still get in.
- Which fitted sheet you use and up to what total height it fits.
There is no fixed rule for everyone. How the bed feels is a matter of taste.
Common heights and what they change
In shops you will roughly find three height classes. The figures are a guide, not a standard:
| Height | Effect on feel | What to look for |
|---|---|---|
| approx. 2–4 cm | subtle, more of an extra padding layer | Hardly noticeable, evens out the base only slightly |
| approx. 5–7 cm | noticeably softer or more cushioning | Check total bed height and sheet |
| approx. 8–12 cm | clearly changed bed | Entry height, sheet, weight and handling |
With foam toppers, the feel depends not only on height but also on material and firmness grade. A 5 cm topper with two foam layers feels different from a 7 cm one made of a single foam layer. On firmness, read the guide Topper firmness.
5 cm (2-in-1 and Dream) compared with 7 cm (Premium)
Here are the three models directly compared:
| Model | Height | Construction | Special feature |
|---|---|---|---|
| Premium Comfort Topper | 7 cm | Gel memory foam, 40 D | Firmness H3, medium-soft (manufacturer's indication) |
| 2-in-1 Comfort Topper | 5 cm | 2 cm gel memory foam (H3, soft) + 3 cm support foam (H4, firm) | reversible |
| Dream Topper | 5 cm | Foam with memory effect | non-slip underside fabric |
The 7 cm Premium Comfort Topper brings more foam volume. That can feel softer and more enveloping. In return it is higher and may be less practical on a bed that is already high.
The two 5 cm toppers are lower. The 2-in-1 Comfort Topper has the advantage that you can try whether you prefer the softer or the firmer side. The Dream Topper is a plain variant made of foam with a memory effect, without a gel component.
Who are the models rather not meant for? If you have a very high bed, you are more likely to choose 5 cm. If you are looking for a clearly changed feel, you may find 5 cm too subtle.
Effect on bed frame and fitted sheet
Every centimetre of topper adds to the total height. For the bed frame, this can mean the sleeping surface moves closer to the top edge of the frame, which is an issue with beds that have a low surround. Check that the mattress with topper does not stick out above the edge.
For the sheet, the pocket depth counts:
- Measure the height of your mattress.
- Add the topper height (5 or 7 cm).
- If needed, allow a small reserve, because according to the warranty terms the height can deviate by up to 1 cm.
- Compare this value with the figure in the product description of your fitted sheet.
A sheet that is too tight tends to slip off at the corners and takes the topper with it. Tips on keeping it in place are in the guide Mattress topper for box spring beds.
Height and mattress firmness
Height works together with the firmness of the base. On a firm mattress, a thicker soft topper makes the difference more noticeable than a thinner one. On an already soft mattress, additional softness can quickly feel very yielding. Please note: firmness grades are not standardised, so an H3 from one manufacturer can feel different from another's. You will find more on classifying your mattress in the article Mattress too hard or too soft.
A topper is also a layer and not a replacement for a badly sagged mattress. If the base has sunk noticeably, even a thicker topper only compensates for part of it.
Body weight and manufacturer's information
How a topper feels under load also depends on body weight. We cannot give generally valid limits here. The information in the product description and in the warranty terms, which apply to each model, is what counts. Please read these before buying if you or your partner are noticeably heavier than average.
For beds for two people of different weights, a uniform feel often cannot be fully achieved. A continuous layer at least provides an even surface; how it feels for both of you remains a matter of taste and can be tried out at home.
Frequently asked questions
How thick should a topper be?
For many beds, 5 to 7 cm is common. Thinner layers change the feel more subtly, thicker ones much more strongly, but also raise the entry height. The right thickness depends on your mattress, your bed and your taste. We offer toppers with 5 cm and 7 cm.
Topper 5 cm or 7 cm: what is the difference?
7 cm means more foam volume and a greater total height, while 5 cm is lower and fits more easily into existing beds. Material and construction also play a role: the Premium Comfort Topper is made of gel memory foam, the 2-in-1 of two layers, the Dream Topper of foam with a memory effect.
Will a topper fit under my fitted sheet?
That depends on the pocket depth of the sheet. Add mattress height and topper height and allow a small reserve, because the height can deviate by up to 1 cm. The permitted total height is in the sheet's product description.
How high does a topper get after unpacking?
The toppers are delivered compressed in the box. After unpacking, lay them out and let them unfold for 24 to 48 hours before judging height and feel. Until then the foam may still look flatter.
I have health complaints. Which topper helps?
No product replaces medical advice. If you have persistent complaints, please talk to a doctor or physiotherapist. Our toppers are not medical products. Here we only describe height and materials as a guide.