Custom Fitted Sheets for Thick Mattresses & Toppers in Hong Kong: How to Measure
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If your fitted sheet keeps popping off a thick mattress, the first number to check is the total mattress height—not just the bed-size label. A deep mattress, pillow-top construction or added topper can make an otherwise correct-looking fitted sheet too shallow.
SIMPLE OL’ ME · THICK-MATTRESS FIT METHOD
We measure the complete sleeping stack
For custom fitted-sheet orders involving a thick mattress or topper, our bedding team uses the actual length × width × total height. If the topper remains on the mattress and the fitted sheet is meant to cover both, the topper must be included in the height measurement.
We also check the bed structure: a heavy mattress recessed into a platform bed can create a different usability problem from a freestanding deep mattress, even when the dimensions are similar.
Why thick mattresses cause fitted sheets to come off
A fitted sheet needs enough depth to travel down the mattress sides and maintain tension underneath. If the mattress is substantially deeper than the sheet was designed for, the corners can be pulled upward during sleep, especially after adding a topper.
How to measure a thick mattress correctly
- Measure the length from top edge to bottom edge.
- Measure the width from side to side.
- Measure the total height from the bottom of the mattress to the top sleeping surface.
- If a topper is always used inside the fitted sheet, include the topper in the total height.
For the general measurement process, see How to Measure a Mattress for Custom Fitted Sheets.
Traditional fitted sheet or detachable zipper fitted sheet?
A traditional custom fitted sheet works well when the mattress can be lifted and the sides are accessible. A detachable zipper fitted sheet can be worth comparing when the mattress is very heavy, recessed into a platform frame, pushed tightly against a wall or otherwise difficult to lift repeatedly.
The zipper option is a construction choice, not a separate fabric grade.
Which fabric should you choose for a thick mattress?
Mattress depth determines fit; fabric determines hand feel. The current traditional custom range has four distinct material directions:
| Material | Feel | Choose it when... |
|---|---|---|
| 100s TENCEL™ Lyocell | Softer, smoother, lighter and more fluid | You prioritise pure-Lyocell softness and drape |
| 120s Fine-Denier Lyocell Cotton | 60% Lyocell + 40% long-staple cotton; fuller and more structured | You want Lyocell smoothness with more body |
| 100s Long-Staple Cotton Sateen | Smooth, dense and more substantial | You prefer a classic premium-cotton hand |
| 140s Cotton Sateen | Finer, lighter and more refined | You prefer a more delicate premium-cotton direction |
Do not treat 100s, 120s and 140s as one automatic quality ranking. Fibre composition and fabric construction are different. See the four-material comparison.
Common thick-mattress scenarios
Deep mattress without a topper
Use the actual mattress height. A custom fitted sheet can be made around that measurement rather than relying on a generic “deep pocket” label.
Mattress plus topper
If the topper stays inside the fitted sheet, measure the combined stack. If the topper is removed frequently or wrapped separately, explain that use case when ordering.
Heavy mattress inside a platform bed
Fit can be correct but changing the sheet can still be difficult. In that case, compare the traditional fitted sheet with the detachable zipper construction.
Imported deep mattress
Use the actual centimetre measurements rather than converting from a regional label such as Queen or King.
Order by actual dimensions
Once the mattress dimensions are confirmed, choose the material and enter the measurements in the product quotation tool:
For all structures and materials, visit the Hong Kong Custom-Made Bedding collection.
Related guides
Complete custom-bedding guide · Odd-size mattress guide · Custom duvet-cover guide
Written by Simple ol’ Me Bedding Team. This guide reflects the fit checks we use when handling made-to-measure fitted sheets for deep mattresses and toppers.