A mattress that measures 18 inches deep needs more than a standard fitted sheet: shallow pockets can pull loose at the corners or bunch up overnight. The options below are designed for deep beds, with stated fits that reach 18 inches or more. Before you buy, measure your mattress with any topper or pad in place, then check that the sheet’s pocket depth and bed size match your setup.
Quick Comparison
| Sheet set | Material | Stated mattress fit | Best for |
|---|---|---|---|
| Shilucheng Egyptian Cotton Sheets | 100% Egyptian cotton | 18–24 inches | Cotton feel and a deep pocket |
| CGK Unlimited Extra Deep King Sheet Set | Microfiber | 18–24 inches | A cozy king-size set with four pillowcases |
| CGK Linens Extra Deep King Fitted Sheet | Double-brushed fabric | 18–24 inches | Replacing just the fitted sheet |
| AiAngu Bamboo-Derived Sheet Set | Rayon derived from bamboo | 18–24 inches | A smooth-feeling, moisture-wicking set |
| CGK Unlimited Extra Deep King Sheet Set | Double-brushed microfiber | 18–24 inches | An adjustable bed or topper setup |
Our Picks: Best Sheets For 18 Deep Mattress reviews
Shilucheng Egyptian Cotton Sheets: Cotton With Extra-Deep Pockets
This set stands out for shoppers who want cotton rather than microfiber or bamboo-derived rayon. Shilucheng describes the sheets as 100% Egyptian cotton and says the fitted sheet is made for mattresses from 18 to 24 inches deep. That range gives you room for a thick mattress plus a topper or pad, as long as the combined height stays within the stated limit.
The set is described as machine washable, with care instructions recommending cold water, a gentle cycle, and low-heat tumble drying. Shilucheng also states that the sheets are OEKO-TEX Standard 100 certified. The set title identifies the size as Queen, but the supplied product details include conflicting King-size measurements. Check the selected size and included pieces on the listing before ordering.
Compared with the microfiber picks here, this is the more natural-fiber option. Cotton may suit shoppers who prefer a familiar woven-sheet feel, but this set may not be the right choice if you specifically want a silky bamboo-derived fabric or a larger pillowcase count.
Pros:
- Listed as 100% Egyptian cotton
- Designed for mattresses 18–24 inches deep
- Machine washable with care instructions provided
- Described as OEKO-TEX Standard 100 certified
Cons:
- Product details contain conflicting Queen and King size information, so confirm the selected option before buying
- The supplied listing details do not specify a thread count
Verdict: Choose this set if cotton is your priority, but verify the size and included pieces carefully because the product details are inconsistent.
CGK Unlimited Six-Piece King Set: Cozy Microfiber With Four Pillowcases
This King-size set is a practical option if your mattress is thick and you want extra pillowcases included. The listing says the fitted sheet is designed for mattresses 18 to 24 inches deep and uses elastic around the edges to help keep it in place. It is also described as suitable for beds with toppers, pads, and pillow tops.
The set includes six pieces: a flat sheet, a fitted sheet, and four pillowcases. The microfiber fabric is described as soft and cozy, with a warmer feel than crisp cotton. That may work well if you like a smooth, plush sheet, but shoppers who prefer the feel of cotton may find microfiber less familiar.
Its key difference from the other CGK Unlimited King set in this list is the four pillowcases and the emphasis on cozy, winter-friendly comfort. The fitted sheet has a stated pocket depth of 21 inches, with elastic that can stretch to fit the wider depth range. If your mattress and topper together are close to the upper limit, measure the full height before choosing.
Pros:
- Designed for mattresses 18–24 inches deep
- Six-piece set includes four pillowcases
- Described as soft and cozy for cooler nights
- Listed as suitable for toppers and pillow-top mattresses
Cons:
- Microfiber may not suit shoppers who prefer cotton’s feel
- The listed fitted-sheet pocket depth is 21 inches, so check your full mattress height against the fit range
Verdict: Pick this set if you have a King bed, want four pillowcases, and prefer soft, cozy microfiber.
CGK Linens Extra Deep King Fitted Sheet: A Simple Replacement
Unlike the other options here, this product is a fitted sheet rather than a full set. That makes it worth considering if your flat sheet and pillowcases are still in good shape, or if you mainly need a deeper sheet that can stay on a thick mattress.
CGK Linens states that it fits mattresses from 18 to 24 inches deep and has elastic all the way around the edge. The fabric is described as double-brushed and machine washable. The listing also claims resistance to tearing, shrinking, wrinkling, staining, and fading, though care habits and washing conditions can affect how any fabric holds up over time.
This is a King-size option, so confirm that it matches your mattress dimensions as well as its depth. Compared with the full sets in this guide, it gives you fewer pieces but lets you replace only the fitted sheet. That can be a sensible choice when the main problem is a fitted sheet that pulls loose.
Pros:
- Fits mattresses stated to be 18–24 inches deep
- All-around elastic is designed to help hold the sheet in place
- Useful when you only need a fitted sheet
- Machine washable
Cons:
- Does not include a flat sheet or pillowcases
- King size will not fit other mattress sizes
Verdict: Choose this fitted sheet if you already have matching bedding and need a deep-pocket replacement for a King mattress.
AiAngu Bamboo-Derived Sheet Set: Smooth Fabric for Warm Sleepers
AiAngu’s set is made from 100% rayon derived from bamboo, according to the product details. The fabric is described as smooth, breathable, and moisture-wicking, which may appeal to people who tend to sleep warm or prefer a silky feel against the skin.
The Queen set includes a flat sheet, a fitted sheet, and two pillowcases. Its stated pocket range is 18 to 24 inches, and the fitted sheet is described as having a double-stitched elastic hem. The listing also describes the fabric as wrinkle- and fade-resistant, though you should follow the care instructions to help maintain its appearance.
Compared with the cotton and microfiber choices, this set puts more emphasis on a smooth drape and moisture management. Keep in mind that “bamboo” in the product title refers to rayon derived from bamboo, not a sheet made from raw bamboo fiber. The supplied details identify the set as Queen, so check the listing if you need another size.
Pros:
- Rayon derived from bamboo is described as smooth and breathable
- Designed for mattresses 18–24 inches deep
- Queen set includes a flat sheet, fitted sheet, and two pillowcases
- Listed with a double-stitched elastic hem
Cons:
- Only the Queen set details are provided here
- Its silky feel may not suit shoppers who prefer crisp cotton sheets
Verdict: Consider this set if you want a Queen-size, bamboo-derived rayon option with a smooth feel and a deep fitted sheet.
CGK Unlimited Four-Piece King Set: Deep Fit for Adjustable Beds
This King-size set is designed for mattresses from 18 to 24 inches deep and is specifically described as suitable for adjustable beds. Its fitted sheet has a 21-inch pocket with stretchable elastic, which is intended to help it stay in place as the bed changes position. It may also work for beds with toppers, pads, or pillow tops.
The four-piece set includes a flat sheet, fitted sheet, and two oversized pillowcases. Its double-brushed microfiber is described as lightweight, breathable, and soft, with wrinkle-resistant performance. Compared with the other CGK Unlimited set in this guide, this one has two pillowcases rather than four and puts more emphasis on adjustability and cooling comfort.
If your adjustable bed has a thick mattress and topper, check the total height and the bed’s dimensions before ordering. The listed pocket depth gives a useful guide, but a sheet’s fit also depends on mattress size and how much material you need to tuck around the base.
Pros:
- Designed for mattresses 18–24 inches deep
- Listed as suitable for adjustable beds and topper setups
- Four-piece King set includes two oversized pillowcases
- Microfiber is described as lightweight and wrinkle resistant
Cons:
- Includes two pillowcases, compared with four in the other CGK Unlimited set
- Microfiber may feel different from cotton or bamboo-derived rayon
Verdict: This is a strong option to consider for a thick King mattress on an adjustable base, especially if you want a lighter microfiber set.
How to Choose Sheets for an 18-Inch-Deep Mattress
Measure the Mattress With Bedding Layers in Place
Measure from the bottom edge of the mattress to its top surface. If you use a topper, mattress pad, or pillow top, include those layers in the measurement. A mattress that is 18 inches deep on its own may need a deeper pocket once extra layers are added.
Check Pocket Depth and Mattress Size
Look for a stated pocket range that covers your total mattress height. Several options here list a fit of 18–24 inches, while some also specify a 21-inch pocket with stretchable elastic. Confirm both the depth and the bed size: a deep King sheet will not fit a Queen mattress just because the pocket is deep enough.
Choose a Fabric That Suits Your Sleep Preferences
The products here include Egyptian cotton, microfiber, and rayon derived from bamboo. The cotton set may suit shoppers who prefer cotton, while microfiber is described as soft and cozy or lightweight, depending on the product. The bamboo-derived rayon set is described as smooth and moisture-wicking. Fabric feel is personal, so consider which qualities matter most to you.
Look at the Full Set Contents
Set sizes vary. Some options include two pillowcases, one includes four, and one product is only a fitted sheet. Check what is included before buying, especially if you need a complete set or have more than two pillows.
Consider Your Bed’s Design
If you have an adjustable base, a fitted sheet described as adjustable-bed friendly may be worth considering. For toppers or pillow-top mattresses, check that the total height remains within the stated fit range. All-around elastic is another feature to look for if your current sheet tends to lift at the corners.
Read the Care Instructions
Follow the instructions for washing and drying, since heat and rough handling can affect fabric over time. For example, the Shilucheng listing recommends a gentle cold-water wash and low-heat tumble drying. Check the care guidance for the exact product you select.
Frequently Asked Questions
Will a standard fitted sheet fit an 18-inch mattress?
It may not. Standard sheets can have pockets that are too shallow, especially if you use a mattress topper or pad. Look for a fitted sheet with a stated depth that covers the mattress and all added layers.
How deep should the pockets be for my mattress?
Measure the mattress with any topper or pad in place, then choose a sheet whose stated fit range includes that measurement. For an 18-inch mattress, a sheet listed for 18–24 inches may be suitable, provided the bed size also matches.
Are deep-pocket sheets suitable for a mattress topper?
They can be, if the combined height of the mattress and topper is within the sheet’s stated range. Measure the whole setup rather than relying on the mattress depth alone.
What’s the difference between a sheet set and a fitted sheet?
A sheet set typically includes a fitted sheet, a flat sheet, and pillowcases. The CGK Linens product in this guide is a fitted sheet only, so it does not replace the rest of your bedding.
Which fabric is best for someone who sleeps warm?
There is no single best fabric for everyone. The AiAngu rayon-derived-from-bamboo set is described as breathable and moisture-wicking, while the CGK Unlimited four-piece set is described as lightweight microfiber. Consider both the fabric description and the feel you prefer.
How do I know which sheet size to buy?
Match the sheet size to your mattress—such as Queen or King—and check the listed dimensions when available. Pocket depth refers to mattress height, not the mattress’s width or length.
Final Recommendation
For a full set with a wide stated depth range, compare the CGK Unlimited and AiAngu options based on bed size, fabric, and how many pillowcases you need. If you prefer cotton, the Shilucheng set is worth considering, but verify its size details because the supplied product information conflicts. For a King bed where only the fitted sheet needs replacing, the CGK Linens option is the most focused choice.