Best Sheets For 18 Inch Mattress

Finding the right sheets for an 18 inch mattress is harder than it looks. Standard fitted sheets usually have a pocket of about 15 inches, so they often pop off the corners of a thick pillow-top, a memory foam topper, or an air mattress. Extra deep pocket sheets solve that problem, but only if the pocket depth matches your bed. This guide covers five extra deep pocket sheet options designed for mattresses in the 18 to 24 inch range. You will find each product’s material, what is included, how it fits real beds, and who it suits best. The buying guide at the end explains how to measure your mattress, compare fabrics, and avoid the most common sizing mistakes.

Quick Comparison Table

Our Picks: Best Sheets For 18 Inch Mattress reviews

Hearth & Harbor Extra Deep Pocket Queen Sheets Set: Full Bedding Value in Microfiber

This is a complete queen set built around an extra deep pocket fitted sheet. It includes one fitted sheet measuring 60 by 80 inches, one flat sheet measuring 90 by 102 inches, and four pillowcases. The fitted sheet is rated for mattresses between 18 and 24 inches deep, which covers most thick pillow-top and hybrid beds. The set is woven from microfiber and brushed on both sides, which gives it a soft, smooth surface.

The main appeal here is completeness. You get the full set in one purchase, and the four pillowcases make it easier to cover multiple sleepers or spare pillows. Microfiber also tends to hold its color and shape well through repeated washing, and the listing describes the fabric as resistant to pilling, snagging, fading, and wrinkling. For a household that does laundry often, that low-maintenance quality matters more than thread count.

Microfiber is not the same as cotton, though. It feels warmer against the skin and does not breathe as well, so hot sleepers may find it less comfortable in summer. Some owners also say the fabric feels slightly synthetic compared with natural cotton, which is a matter of personal preference. The listing describes the set as pet-friendly, which can help if animals share the bed. Compared with the cotton options in this guide, this set makes more sense for buyers who value convenience and a full set over a natural fiber feel.

Pros:

• Complete queen set with a fitted sheet, flat sheet, and four pillowcases
• Extra deep pocket fits mattresses from 18 to 24 inches
• Brushed microfiber feels soft and resists pilling and wrinkling
• Machine washable in cold water and dries quickly on low heat

Cons:

• Microfiber can trap heat, which may bother hot sleepers

Verdict: This set is a strong choice for shoppers who want a full, low-fuss bedding package that fits thick mattresses. It is best for everyday use, families, and anyone who prioritizes easy care over a natural fiber feel.

Shilucheng 100% Egyptian Cotton Sheets Set: A Natural Cotton Option for Thick Mattresses

This set is made from 100% Egyptian cotton and includes a fitted sheet measuring 60 by 80 inches with a 20 inch pocket, a flat sheet measuring 90 by 102 inches, and two pillowcases. The listing says the fitted sheet fits mattresses between 18 and 24 inches, including double pillow-top beds, memory foam toppers, mattress pads, and air mattresses. The product is also listed as certified to OEKO-TEX Standard 100, which tests textiles for harmful substances.

Cotton is a natural fiber, and it generally breathes better than microfiber or polyester blends. Buyers who sleep warm or prefer a crisp, lightweight feel often find cotton more comfortable through the seasons. The listing describes the material as suitable year-round, which is a reasonable claim for cotton, since it allows air to move through the fabric. Some owners find that cotton softens with each wash, while others notice it wrinkles more easily than synthetic fabrics.

There are a few details to check before buying. The product title lists a queen size, but parts of the description refer to a king sheet set. Confirm the exact dimensions on the product page and measure your mattress before ordering. The set also includes only two pillowcases, so buyers who want more may need an extra pair. Care instructions call for cold water, a gentle cycle, and low-temperature drying, which is typical for natural cotton. Compared with the microfiber set, this option trades some wrinkle resistance for better breathability and a more natural fabric feel.

Pros:

• 100% Egyptian cotton offers a natural, breathable feel
• Extra deep pocket fits mattresses from 18 to 24 inches
• Listed as OEKO-TEX Standard 100 certified
• Works well for layering over thick mattress toppers

Cons:

• Only two pillowcases are included, and the sizing details in the listing should be double-checked

Verdict: This is a good pick for buyers who want cotton sheets that fit deep mattresses and breathe well through the seasons. It suits shoppers who value a natural fiber and are willing to accept some wrinkling in exchange for comfort.

Bedecor Extra Deep Pocket Fitted Sheet in Twin XL: A Focused Option for Layering

This is a single fitted sheet, not a full bedding set. It is designed for mattresses between 18 and 24 inches and includes a storage bag for convenience. The product is made from double-brushed polyester microfiber and features elastic running around the entire perimeter, not only the corners. That design is meant to keep the sheet tight across the whole mattress, which is helpful on beds that shift during the night.

The fitted-only format is the main point to understand. If you already own flat sheets and pillowcases that you like, this option lets you replace just the part that wears out or fails to fit. It is also a practical choice for guest rooms, kids’ beds, or RVs. The listing says the sheet comes in several colors and sizes from Twin through California King, so you can match your existing bedding or pick a neutral shade.

The listing includes an important warning. On mattresses under 16 inches, the extra deep pocket leaves excess fabric that cannot pull tight. Measure your mattress height, including any topper, before ordering. Buyers who select a size without checking depth may end up with a loose, bunched fitted sheet. Compared with the full sets in this guide, this option costs less effort to manage and is more flexible, but you will need to supply the flat sheet and pillowcases yourself.

Pros:

• Full-perimeter elastic helps keep the sheet secure across the mattress
• Double-brushed microfiber resists wrinkles, so ironing is usually unnecessary
• Storage bag makes it easy to store when not in use
• Available in several colors and sizes from Twin through California King

Cons:

• Does not include a flat sheet or pillowcases, so it is not a complete set

Verdict: This fitted sheet is a smart choice for shoppers who need an extra deep pocket fit but already have other bedding. It is especially useful for guest rooms, kids’ beds, and RVs. Confirm your mattress depth before buying, because this sheet is not designed for thinner beds.

SONORO KATE 1000 Series Egyptian Cotton Queen Sheets: Certified Cotton With a Crisp Finish

This queen set is made from 100% Egyptian cotton and is described as 1000 thread count. It includes a fully elasticized fitted sheet measuring 60 by 80 inches, a flat sheet measuring 90 by 102 inches, and two pillowcases measuring 20 by 30 inches. The fitted sheet is designed for mattresses between 18 and 24 inches deep and uses a 360-degree elastic band to grip the mattress more securely than standard sheets.

What sets this set apart is its certifications. The listing says every dye, material, and finished product is OEKO-TEX and GOTS certified, which means the materials and processing meet recognized standards for safety and organic textile production. For buyers who care about how their bedding is made, that information carries real weight. The cotton also gives a cool, crisp feel that suits people who sleep warm.

The care instructions are straightforward. Wash on a low setting, tumble dry, and iron on low heat if needed. The listing notes that the sheets resist wrinkling, but cotton of this type still tends to need some attention after drying, especially if you prefer a perfectly smooth look. Some buyers may also find that high thread-count cotton feels firmer at first and softens over time. Compared with the other cotton option in this guide, this set offers more included pieces and stronger certification details, though it still requires slightly more care than microfiber.

Pros:

• Certified materials and dyes, including OEKO-TEX and GOTS
• Complete queen set with a fitted sheet, flat sheet, and two pillowcases
• Elastic band runs around the fitted sheet for a snug fit on deep mattresses
• Cotton construction supports airflow and a cool sleeping feel

Cons:

• Cotton needs ironing or careful drying to look its smoothest

Verdict: This set is a strong option for shoppers who want certified cotton bedding that fits mattresses up to 24 inches deep. It is well suited to buyers who sleep warm and appreciate a crisp, natural feel, as long as they are comfortable with a bit of extra care during laundry.

AiAngu Bamboo-Derived Viscose Sheet Set: A Cooling Choice for Hot Sleepers

This four-piece queen set is made from 100% rayon derived from bamboo, often called viscose. It includes a flat sheet measuring 92 by 102 inches, a fitted sheet measuring 60 by 80 inches, and two pillowcases measuring 20 by 30 inches. The fitted sheet is designed for mattresses between 18 and 24 inches deep and uses a double-stitched elastic hem to help it stay in place.

The biggest difference from the other choices is the fabric itself. Bamboo-derived viscose has a smooth, drapey feel that many people find silky. The listing describes the fabric as naturally breathable and moisture-wicking, which suits people who wake up warm or sweat during the night. The twill weave is also described as more durable than standard cotton in this product’s listing, which adds a practical benefit for everyday use.

Be aware that viscose behaves differently from cotton. It can feel cooler and slippery, which some sleepers love and others dislike. It also tends to need gentle care, and fabrics like this can lose some structure if washed or dried too aggressively. The listing mentions minimal ironing after washing, but you should still follow the care instructions closely. Compared with the cotton sets, this option is a better fit for hot sleepers who want a cooling, silky surface rather than a traditional cotton finish.

Pros:

• Bamboo-derived viscose has a smooth, silky feel and drapes softly over the mattress
• Four-piece queen set includes a flat sheet, fitted sheet, and two pillowcases
• Breathable, moisture-wicking fabric suits warm sleepers
• Double-stitched elastic hem helps the fitted sheet stay in place on deep mattresses

Cons:

• Viscose requires gentle care and may not hold up as well to rough washing or high heat

Verdict: This set is a good match for hot sleepers who want a cool, silky feel on a deep mattress. It is less suited to buyers who expect the crisp structure of cotton or who put bedding through frequent hot-water washes.

How to Choose the Right Sheets for an 18 Inch Mattress

Measure Your Mattress Depth Accurately

Before you shop, measure your mattress from the bottom edge to the top surface. Include any mattress topper, pad, or pillow-top layer, since these add to the total height. Fitted sheets are sized by pocket depth, and the pocket needs to wrap around the mattress without leaving a lot of extra fabric or pulling too tight. Most of the sheets in this guide are designed for depths from 18 to 24 inches, so an 18 inch mattress sits at the lower end of that range. Measuring carefully helps you avoid a sheet that slides off or bunches up underneath.

Understanding Pocket Depth and Elastic Design

An extra deep pocket is not the same as a standard fitted sheet with a bit more fabric. The pocket is deeper and longer, which allows it to fold under a thick mattress and stay attached. Look for sheets with elastic that runs around the full perimeter, not only at the corners. Full-perimeter elastic distributes tension more evenly and helps the sheet keep its shape through the night. A double-stitched elastic hem is another useful sign of durable construction, since the elastic is the part most likely to loosen over time.

Comparing Microfiber, Cotton, and Bamboo-Derived Fabrics

Fabric is the biggest factor in how a sheet feels and performs. Microfiber is smooth, soft, and generally resistant to wrinkling and fading, which makes it practical for busy households. Its main drawback is that it can trap heat. Cotton, especially Egyptian cotton, breathes better and feels crisp, but it usually needs more care and can wrinkle more easily. Bamboo-derived viscose offers a silky, cooling surface that many warm sleepers appreciate, though it needs gentler handling. Think about how you sleep, how often you do laundry, and whether a cooler or warmer feel suits you best.

Breathability and Temperature Comfort

If you tend to sleep warm, pay close attention to how the fabric handles heat. Natural fibers like cotton and viscose generally allow more air to move across the surface than tightly woven microfiber. However, the weave and finish also matter. A thick, heavily brushed sheet may feel warmer than a lightweight one even if both are made from similar fibers. Since a thick mattress already holds heat, choosing a breathable sheet can make a noticeable difference in comfort during summer months.

Care, Laundering, and Long-Term Durability

Care instructions affect how long your sheets last. Most of the options here recommend cold or cool water, gentle cycles, and low-heat drying. Following these steps helps protect the elastic and keeps the fabric soft. Microfiber is typically the easiest to maintain, while cotton and viscose reward careful handling with a longer life and better appearance. Washing sheets of similar colors together reduces fading, and avoiding high heat prevents shrinking and elastic breakdown.

Choosing Between a Full Set and a Fitted Sheet Only

A full set makes sense if you are replacing all your bedding or setting up a new bed. It saves time and ensures the pieces match. A fitted-only sheet is more useful if you already have flat sheets and pillowcases you like, or if you need a spare for a guest room or kids’ bed. Consider how many sleepers use the bed and whether you want backups on hand. Matching the set contents to your actual needs avoids paying for pieces you will not use.

Certifications and Material Transparency

Some sheets list certifications such as OEKO-TEX or GOTS. These labels indicate that the materials or processing have been checked against specific standards. They do not guarantee comfort, but they can help buyers who want more confidence in what their bedding is made from. When a product lists its fiber content, thread count, and care instructions clearly, that transparency makes comparison shopping easier. Always read the full product description to confirm the materials and dimensions before ordering.

Frequently Asked Questions

What does “extra deep pocket” mean for an 18 inch mattress?

An extra deep pocket sheet has a fitted section designed to wrap around taller mattresses. The pockets in this guide are rated for mattresses from 18 to 24 inches deep, so an 18 inch mattress falls within that range. Standard fitted sheets usually fit up to about 15 inches, which is why they often come loose on thick beds.

Should I measure my mattress with a topper included?

Yes. If you use a mattress topper, pad, or pillow-top layer, include its height in your measurement. The total depth is what matters for the fitted sheet. Measuring only the base mattress can lead you to choose a pocket that is too shallow or too loose.

Will extra deep sheets fit a thinner mattress?

Not always. Extra deep pockets are designed for thicker beds. On mattresses under about 16 inches, the extra fabric may not pull tight and can bunch underneath. If your mattress is thinner, look for a standard-pocket fitted sheet instead.

Is microfiber or cotton better for a thick mattress?

It depends on your preferences. Microfiber is wrinkle-resistant and easy to care for, but it can feel warmer. Cotton breathes better and has a crisp feel, though it usually needs more careful laundering. If you sleep warm, a breathable natural fiber may be more comfortable. If you want low-maintenance bedding, microfiber is often the easier choice.

Can I dry extra deep pocket sheets in the dryer?

Most of the sheets in this guide recommend tumble drying on low heat. High heat can weaken elastic over time and cause shrinking or fading. Low heat is gentler on the fabric and helps the fitted sheet keep its fit for longer.

Are bamboo-derived sheets a good choice for hot sleepers?

They can be. Bamboo-derived viscose has a smooth, breathable feel that many warm sleepers prefer. It drapes softly and can feel cooler than some other fabrics. However, it requires gentle washing, so it may not suit someone who wants sheets that handle rough laundering.

Should I buy a full set or just a fitted sheet?

Buy a full set if you need complete bedding or are setting up a new bed. Choose a fitted-only sheet if you already own flat sheets and pillowcases, or if you need a spare for a guest room, child’s bed, or RV. The right choice depends on what you already have and how many sheets you need to keep on hand.

Final Recommendation

For most buyers with an 18 inch mattress, the best choice depends on what matters most. If you want a complete, low-maintenance set, the Hearth & Harbor microfiber queen set offers a full package that fits deep beds and is easy to keep looking neat. If you prefer natural fibers and a breathable feel, the Shilucheng Egyptian cotton set and the SONORO KATE certified cotton set are both solid options, with the SONORO KATE set offering more certification detail and a more complete set of included pieces. Hot sleepers who want a cool, silky surface should look closely at the AiAngu bamboo-derived viscose set. If you already have bedding and only need a deep fitted sheet, the Bedecor fitted sheet is a practical and flexible choice. Whatever you choose, measure your mattress depth first, check the pocket range against your bed, and confirm the included pieces before you buy.