Quick take: Deep pocket fitted sheets are made for taller mattresses.

• Standard fitted sheets usually fit up to about 14 inches deep.
• Deep pocket styles often fit roughly 14–16 inches.
• Extra deep options are designed for even thicker builds, commonly about 18–24 inches.

Check the product description for phrasing like “fits up to X inches” and match it to your mattress depth, including any topper. On Walmart.com, filters can help you narrow by mattress size and pocket depth, and customer reviews may offer real‑world fit notes. Choosing the right pocket can reduce slipping and make tucking the sheet easier, but fit can vary by mattress and sheet design.

Here’s a simple order that many people use:

1. Fitted sheet: Goes on first, hugging the mattress. For deep pocket styles, align any size or care tag at the foot, place the deeper corners over the thicker end, and pull each corner firmly under the mattress.
2. Flat (top) sheet: Lay it evenly, finished side facing down so the good side is against you when folded back.
3. Blanket/comforter: Add your preferred layer for warmth.
4. Pillows and shams: Finish with pillows.

Some deep pocket fitted sheets include features like all-around elastic or storage pockets at the sides; when present, make sure those pockets face outward for easier access.

Measure in a few quick steps:

1. Remove bedding so you’re measuring the mattress directly, including any topper.
2. Use a tape measure from the bottom edge of the mattress to the highest point on top. That number is your depth.
3. Add a little wiggle room (about 1–2 inches) to allow for tuck and variations between brands.
4. Match to product details: Look for listings that state “fits up to X inches” and choose the closest pocket size.

On Walmart.com, you can filter by mattress size and pocket fit, then review product descriptions and customer feedback to gauge how snug or generous the cut feels. If you’re between sizes, a slightly larger pocket may be easier to put on, but too large can loosen the hold.

It depends on your combined mattress height.

• Measure total depth: Mattress plus any pillow-top or foam topper.
• Compare to pocket range: If your total height exceeds the listed deep pocket range, consider extra deep options (often around 18–24 inches).
• Fit features: All-around elastic and reinforced corners can help accommodate added bulk without excessive shifting.

When shopping, look for the “fits up to X inches” detail and aim for a pocket that’s close to your measured depth. This approach can help reduce pop-offs during the night while still allowing an easy on/off. If you’re uncertain, customer reviews may offer insights on how a sheet handles toppers of similar thickness.

Good fit and a few setup tips can help:

• Confirm sizing: Match your mattress depth to the sheet’s stated pocket. Oversized pockets can loosen grip.
• Pre-wash: A wash before first use may help the fabric sit snugger (follow care instructions).
• Corner method: Start with the top corners, then pull the bottom corners down and under. Keep tension as you tuck all sides.
• Use included features: If your sheet has all-around elastic or corner straps, position and secure them as designed.
• Accessories: Sheet grippers or suspenders can add hold if needed.

Results can vary by fabric and mattress surface, so a bit of trial and adjustment may be helpful.