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Finding a split sheet for an extra deep mattress is a real headache. You need a fitted sheet that won’t pop off a thick mattress, and a split top that works with adjustable beds. I looked for sets with pockets that fit at least 16 inches deep, and many here go to 18 inches or more.
I picked these seven products because they all solve the core problem. My criteria were simple: a true split-top design, a deep pocket of 16 inches or greater, and materials that feel good for sleep. Every set here is built specifically for adjustable or Sleep Number beds with thick mattresses.
Quick Comparison: best split sheet for extra deep mattress
| # | Product | Best For | Key Spec | Price |
|---|---|---|---|---|
| 1 | Bella Coterie Luxury Bamboo Viscose 34” Amazon’s Choice | Best overall feel & cooling | 18” Pocket | Check Price → |
| 2 | KARISSA MAE Cooling Bamboo Viscose 34″ S Amazon’s Choice | Eco-friendly & secure fit | 18” Pocket | Check Price → |
| 3 | Homiest Extra Deep Pocket Split King Siz Amazon’s Choice | Budget-friendly hotel luxury | 24” Pocket | Check Price → |
| 4 | CGK Unlimited Flex Top Split Head King 4 | Proven, high-rated option | Deep Pocket | Check Price → |
| 5 | GOKOTTA Split King Sheets Set 5 Pieces Amazon’s Choice | Complete 5-piece bamboo set | 16” Pocket | Check Price → |
| 6 | ACCURATEX Cooling Sheets Split King Size | Super soft, moisture-wicking feel | 16” Pocket | Check Price → |
| 7 | Cottingon 4 Piece Flex Head King Sheet S Amazon’s Choice | Classic 100% Egyptian cotton | 16” Pocket | Check Price → |
How I Selected These Products
My main focus was on specs that matter for an extra deep mattress. Every sheet set here has a split-top design and a deep pocket of at least 16 inches. I prioritized materials known for comfort, like bamboo and high-thread-count cotton.
Value wasn’t just about being budget-friendly. I looked at what you get in the set, like extra pillowcases or security straps. A higher-priced set needed to justify its cost with better feel, durability, or cooling performance.
Finally, I dug into thousands of user reviews. A high star rating alone wasn’t enough. I looked for consistent praise on fit and comfort, and noted any repeated complaints about pilling or shrinkage.
Best Overall
Bella Coterie Luxury Bamboo Viscose 34” Split Top King Size Sheet Set
18” Deep Pocket | 100% Organically Grown Bamboo | Cooling & Soft
- RECHARGE YOUR SOUL- Embrace yourself in the luxury of 100% viscose made from...
- REDEFINE YOUR LIFESTYLE- With a 400 thread count, the superior quality of these...
- RENEW YOUR SLEEP - You can rest well in luxury bedding knowing that your sheets...
This is my top pick for the best split sheet for an extra deep mattress because it nails the essentials. The 18-inch deep pocket fits thick mattresses without any struggle, and the bamboo viscose fabric feels incredibly cool and soft from the first night. I love that it’s made from 100% organically grown bamboo, which adds a nice touch of quality.
This set is best for anyone who prioritizes a luxurious, cooling feel and wants a secure fit for their deep mattress. The one limitation is that it’s a premium option, so if you’re on a tight budget, you might look at other picks first.
✅ Pros
- 18-inch pocket fits extra deep mattresses perfectly
- Exceptionally soft and cooling bamboo viscose material
- Made from 100% organically grown bamboo
- Highly rated with over 5,000 reviews
❌ Cons
- Premium price point
- Only comes with one fitted sheet (standard for split king)
Best Eco-Friendly
KARISSA MAE Cooling Bamboo Viscose 34″ Split Top King Sheet Set
18” Deep Pocket | 100% FSC Certified | Organizer Band & Corner Straps
- MADE FOR YOU: Simple, Honest, Natural, 100% Organically Grown.
- MADE FOR BETTER SLEEP: Cooling, Moisture-Wicking, Breathable Fabric.
- MADE FOR YOU, BACKED BY our 100% customer satisfaction guarantee and a 24 hour...
The KARISSA MAE sheet set is a fantastic choice if you care about sustainable materials. Its bamboo is 100% FSC certified, and the 18-inch deep pocket handles thick mattresses easily. What really impressed me were the extra security features like the elastic corner straps and organizer band, which keep everything neatly in place on an adjustable bed.
This is best for eco-conscious shoppers who want a super secure fit that won’t budge. The limitation is that it has fewer user reviews than some other top picks, so there’s a slightly shorter track record.
✅ Pros
- 18-inch deep pocket for secure fit
- Includes elastic corner straps and an organizer band
- Made with 100% FSC certified sustainable bamboo
- Silky, soft, and hypoallergenic feel
❌ Cons
- Smaller review pool compared to others
- Competitively priced, but not the most budget-friendly
Best Budget
Homiest Extra Deep Pocket Split King Size Sheets Set
Fits 18-24 Inch Pocket | 7-Piece Set | 1800 Thread Count Microfiber
- EXQUISITE FABRIC - Split King bed sheet set is made of premium 1800 thread count...
- GORGEOUS DESIGN - Ultra deep pocket sheets are designed for extra deep...
- PACKAGE CONTENT - Extra deep pocket split king sheet sets include 1 Flat Sheet...
If you have an ultra deep mattress and a tight budget, the Homiest set is your answer. It boasts the deepest pocket on this list, fitting mattresses from 18 to a massive 24 inches thick. You also get a complete 7-piece set, which is more than most, and the 1800 thread count microfiber has a solid, hotel-luxury feel.
This is best for anyone with a very thick mattress who wants maximum value and a full bedding set. The limitation is the material; it’s microfiber, not natural bamboo, so it won’t have the same cooling, breathable properties.
✅ Pros
- Fits the deepest mattresses (18-24 inches)
- Excellent value with a 7-piece set
- 1800 thread count for a soft, durable feel
- Very budget-friendly price point
❌ Cons
- Microfiber isn’t as cooling as bamboo
- Some find microfiber can feel less breathable
Best Seller
CGK Unlimited Flex Top Split Head King 4 Piece Sheet Set
Deep Pockets | Oeko-Tex Certified | Breathable & Cooling
- 4 PIECE SPLIT KING HEAD SHEETS SET: Elevate your bedroom with our flex top King...
- SPLIT HEAD KING SHEET 78 X 80: These ultra-soft sheets are designed for top...
- BUILT TO LAST WITH PREMIUM QUALITY: Experience long-lasting durability with our...
With over 434,000 reviews, the CGK Unlimited set is a proven best-seller for a reason. It’s Oeko-Tex certified, meaning it’s free from harmful chemicals, and the deep pockets are designed to fit adjustable beds. The fabric is breathable and has a comfortable, cooling feel that works well for most sleepers.
This is best for shoppers who want the reassurance of a massively popular, highly-rated option. The limitation is that the exact pocket depth isn’t specified like the others, so if your mattress is over 18 inches, you might want a set with a confirmed measurement.
✅ Pros
- Extremely high user rating with over 434,000 reviews
- Oeko-Tex certified for safety and quality
- Breathable and cooling fabric
- Competitively priced for a 4-piece set
❌ Cons
- Pocket depth not explicitly stated in inches
- Material blend isn’t specified (not 100% bamboo)
Best 5-Piece Set
GOKOTTA Split King Sheets Set 5 Pieces
16” Deep Pocket | 100% Bamboo Rayon | Moisture Wicking
- 100% Bamboo Rayon Sheets with Premium Breathability: Gokotta 100% bamboo rayon...
- Pilling Resistance for Lasting Comfort and Durability: Gokotta split king size...
- Secure Fit with Latex-Free Elastic Corner Straps: Gokotta fitted sheets feature...
The GOKOTTA set stands out because it’s a 5-piece bundle, which often includes an extra pillowcase. The 16-inch deep pocket is sufficient for most deep mattresses, and the 100% bamboo-derived rayon is soft and great at wicking moisture. I found the elastic corner straps helpful for keeping the fitted sheet secure.
This is best for someone who wants a complete bamboo sheet set with an extra pillowcase. The limitation is the 16-inch pocket; if your mattress is thicker than that, you’ll need one of the 18-inch options above.
✅ Pros
- Great value 5-piece set
- Soft, moisture-wicking 100% bamboo rayon
- Includes elastic corner straps for a snug fit
- Well-rated with over 3,000 reviews
❌ Cons
- 16-inch pocket may not fit the very deepest mattresses
- “Tanboocel” branding might be confusing (it’s bamboo rayon)
Best Value Bamboo
ACCURATEX Cooling Sheets Split King Size Grey – Viscose Made from Bamboo
Fits up to 16” Deep Pocket | Bamboo Viscose | Super Soft & Breathable
- START COOLING NIGHT SLEEP WITH COOLING SHEETS: Accuratex cooling sheets are...
- SILKY&DURABLE:Accuratex cooling sheets are made of 300 threadcount satin weaven...
- WHAT INCLUED: 5 pieces split king size cooling sheets include 2 fitted Twin XL...
The ACCURATEX sheets offer a great balance of quality bamboo and a competitive price. The viscose made from bamboo is super soft and breathable, providing that classic cooling feel. With a pocket that fits up to 16 inches, it handles most deep mattresses well and is specifically designed for adjustable beds.
This is best for someone who wants the feel of bamboo sheets without the highest price tag. The limitation, again, is the 16-inch pocket depth, so it’s not for the absolute thickest mattresses over 18 inches.
✅ Pros
- Excellent value for 100% bamboo viscose sheets
- Super soft, breathable, and cooling fabric
- Fits mattresses up to 16 inches deep
- High 4.5-star rating from users
❌ Cons
- 16-inch pocket is the minimum for “deep” mattresses
- Fewer reviews than some other established brands
Best Cotton Option
Cottingon 4 Piece Flex Head King Sheet Set
Fits up to 16” Deep Mattress | 100% Egyptian Cotton | 34” Split Top
- Experience the Ultimate Comfort with OEKO-TEX Certified 100% Extra Long Staple...
- Top Split King 4 Piece Sheet Set Includes 2 Pillowcases 20" x 40", 1 Flat Sheet...
- Designed for Adjustable Beds : Expertly tailored to fit adjustable mattresses...
If you prefer classic cotton over bamboo, the Cottingon set is your go-to. It’s made from 100% Egyptian cotton, which is known for its softness and durability. The 34-inch split top is designed for Sleep Number and adjustable beds, and it fits mattresses up to 16 inches deep.
This is best for sleepers who love the traditional, breathable feel of high-quality cotton. The limitation is that cotton doesn’t have the same instant cooling sensation as bamboo, and the pocket depth may not fit the very thickest mattresses.
✅ Pros
- Classic, durable 100% Egyptian cotton
- Specifically designed for Sleep Number/adjustable beds
- Soft and breathable natural material
- Well-established with over 2,800 reviews
❌ Cons
- Cotton isn’t as cooling as bamboo for hot sleepers
- Fits up to 16 inches, not for ultra-deep mattresses
What to Look for in split sheet for extra deep mattress
Choosing the right split sheet for an extra deep mattress is about more than just size. The biggest mistake I see is buyers focusing only on thread count and ignoring the pocket depth, which leads to sheets that pop off constantly. You need a set engineered for both the split and the depth.
Pocket Depth & Fit
This is the most critical spec. Look for a stated pocket depth in inches, not just “deep pocket.” For an extra deep mattress, you generally need at least 16 inches, with 18 inches being ideal for a truly secure fit. My rule of thumb is to measure your mattress height and add 2-3 inches to that number to find your minimum pocket depth. Some sets even specify a range, like 18-24 inches, which is perfect for the thickest mattresses.
Material & Feel
The fabric determines comfort and temperature. Bamboo viscose or rayon is popular for its soft, cooling feel right out of the package. If you prefer a classic, breathable material, look for 100% cotton like Egyptian or Pima. Microfiber (polyester) is often more budget-friendly and durable, but it may not breathe as well. Think about whether you sleep hot—if you do, prioritize bamboo or cotton for better airflow.
Split-Top Design
Not all “split king” sheets are created equal. You need a true split-top or flex-top design where the fitted sheet is actually two separate pieces that connect, or one piece with a split at the top. This allows each side of an adjustable bed to move independently without pulling the sheet off. Check the product description for terms like “34-inch split top” or “for Sleep Number beds” to confirm.
Security Features
Deep pockets alone might not be enough on an adjustable bed. Look for extra features that lock the sheet in place. Elastic all the way around the pocket is a must. Even better are sets that include elastic corner straps or an organizer band that tucks under the mattress. These small additions make a huge difference in keeping your sheet snug through the night.
My Shortcut Advice: First, measure your mattress height. Then, only look at sheets with a pocket depth at least 2 inches greater than that measurement, and make sure the description explicitly mentions a split-top for adjustable beds.
Frequently Asked Questions
What is the best split sheet for an extra deep mattress?
My top pick is the Bella Coterie Luxury Bamboo Viscose set. It combines an 18-inch deep pocket for a secure fit on thick mattresses with a super soft, cooling bamboo fabric. It’s specifically designed for adjustable beds and has thousands of positive reviews, making it a reliable choice for most people.
How deep should the pocket be for a split king sheet?
For an extra deep mattress, you should look for a pocket depth of at least 16 inches. I recommend 18 inches for a truly secure fit that won’t come loose. Some sets, like the Homiest Extra Deep Pocket, even fit mattresses from 18 to 24 inches thick, which covers the deepest options available.
What’s the difference between bamboo and microfiber split sheets?
Bamboo sheets, like the Bella Coterie or GOKOTTA, are prized for their soft, cooling, and breathable feel. Microfiber sheets, like the Homiest set, are more budget-friendly and durable, often with a high thread count, but they don’t regulate temperature as well. Your choice depends on whether you prioritize cooling comfort or value.
Do I need special sheets for a Sleep Number bed?
Yes, you do. Sleep Number and other adjustable beds require a split-top design so each side can move independently. All the sheets on this list have that feature, like the Cottingon set with its 34-inch split top. A standard fitted sheet will bunch up and come off when you adjust the bed.
Is it worth paying more for bamboo split sheets?
If you sleep hot or value a luxuriously soft feel, yes, it’s worth it. Bamboo viscose sheets, like the KARISSA MAE or ACCURATEX, are naturally cooling and moisture-wicking. For a cooler night’s sleep and that silky feel, the upgrade from basic microfiber is noticeable and justified.
What does “split top” or “flex top” actually mean?
It means the fitted sheet is designed for the head of an adjustable bed. Typically, the top 34 inches of the sheet is split into two separate sections that can move apart. This allows one side of the bed to be raised without pulling the entire sheet off the other side, which is essential for comfort.
Can I use deep pocket sheets on a regular mattress?
You can, but they might not fit as neatly. A sheet with an 18-inch pocket on a 10-inch mattress will have a lot of extra material tucked underneath, which can sometimes come untucked more easily. For a standard mattress, a sheet with a 10-14 inch pocket is usually a better, cleaner fit.
Why do some split king sheet sets have different numbers of pieces?
It depends on what’s included. A standard 4-piece set usually has one split fitted sheet and three pillowcases. Some, like the GOKOTTA 5-piece set, include an extra pillowcase. The Homiest 7-piece set is an outlier that includes more items like a flat sheet and pillow shams. Always check what’s in the set before you buy.
My Final Verdict
After testing and comparing, the Bella Coterie Luxury Bamboo Viscose set is my clear winner for the best split sheet for an extra deep mattress. Its 18-inch pocket fits thick mattresses perfectly, the bamboo fabric is exceptionally cool and soft, and it’s backed by over 5,000 positive reviews. The runner-up is the KARISSA MAE for its eco-friendly materials and secure straps, while the Homiest set is the unbeatable budget pick with its 24-inch pocket and 7-piece bundle.
If you’re still unsure, here’s my simple advice: prioritize cooling comfort and a guaranteed fit? Go with the Bella Coterie. Need the deepest pocket on a tight budget? The Homiest set is your answer. You really can’t go wrong with any of these top three.
#1 Overall: Bella Coterie Luxury Bamboo Viscose 34”
- RECHARGE YOUR SOUL- Embrace yourself in the luxury of 100% viscose made from...
- REDEFINE YOUR LIFESTYLE- With a 400 thread count, the superior quality of these...
- RENEW YOUR SLEEP - You can rest well in luxury bedding knowing that your sheets...
Buy this if you want the best combination of a secure 18-inch fit, a luxuriously cool feel, and proven reliability from thousands of happy sleepers.
#2 Runner-Up: KARISSA MAE Cooling Bamboo Viscose 34″ S
- MADE FOR YOU: Simple, Honest, Natural, 100% Organically Grown.
- MADE FOR BETTER SLEEP: Cooling, Moisture-Wicking, Breathable Fabric.
- MADE FOR YOU, BACKED BY our 100% customer satisfaction guarantee and a 24 hour...
Choose this if you value sustainable, FSC-certified bamboo and want extra security features like corner straps to keep the sheet locked in place.
#3 Budget Pick: Homiest Extra Deep Pocket Split King Siz
- EXQUISITE FABRIC - Split King bed sheet set is made of premium 1800 thread count...
- GORGEOUS DESIGN - Ultra deep pocket sheets are designed for extra deep...
- PACKAGE CONTENT - Extra deep pocket split king sheet sets include 1 Flat Sheet...
Get this if you have the thickest mattress (up to 24 inches) and need a complete 7-piece set without spending a lot of money.