Deep Pocket Sheets: How to Measure & Get a Fit That Stays Put

There is a special kind of 6 a.m. annoyance that comes from a fitted sheet letting go of the corner and balling up under your back. Nine times out of ten it is not a cheap sheet, it is the wrong depth. Thick pillow-top mattresses and added toppers have quietly gotten taller over the years, and standard sheets simply cannot reach around them. The fix is a proper set of deep pocket sheets. Here is how to measure for them, what the depth numbers mean, and how to make sure they actually stay put.

What counts as a deep pocket?

Pocket depth is just how tall a mattress the fitted sheet can wrap around. There is no single legal standard, but the industry lines up roughly like this, and it is the fastest way to know which deep pocket fitted sheet you actually need.

Most beds sold today land in the deep pocket range, which is why a set that fit your old mattress suddenly gives up on a new one. If you have added a memory-foam topper, you have likely pushed into extra deep pocket fitted sheet territory without realising it.

How to measure your mattress depth

This takes thirty seconds and saves a return. Do it before you buy any deep pocket sheets.

• 1.Strip the bed and stand a tape measure upright against the side of the mattress.
• 2.Measure from the bottom seam to the top seam. That is your mattress height.
• 3.Add the thickness of any mattress topper you use on top.
• 4.Add about 2 inches of breathing room, and match that total to the pocket sizes above.

Depth alone will not keep a sheet on

Here is the part most brands skip. A pocket can be deep enough and the sheet still slides off, because the elastic only runs across the corners. When you sit on the edge or roll over, the unelasticated sides lift. The fix is 360-degree all-around elastic, which is sewn along the entire opening so the sheet hugs the mattress on every side. Every SGI deep pocket fitted sheet is built this way, which is the real reason it stays anchored where a corner-only sheet lets go.

Our Pick

600TC Cotton Deep Pocket Sheet Set

• 15" deep pockets, 360-degree all-around elastic
• 100% long-staple cotton, 4-piece set, 9 colors
• Sizes Twin through California King and RV King

From $48.99

Shop the set

Want the deepest option? Our 1000 thread count Egyptian cotton set steps the pocket up to a full 18 inches with the same all-around elastic, and it feels silkier too. If you are still deciding on a weave, our guide to the best thread count for sheets breaks down the trade-offs.

What if your mattress is deeper than 18 inches?

Some stacked setups, adjustable beds, and older heirloom mattresses run past even an extra deep pocket. Rather than fight an off-the-shelf size, our custom size sheets are cut to the exact height you measured, so the fit is guaranteed no matter how tall the bed. It is the simplest answer for anything outside the standard range. For more on picking the right material for a deep bed, see our Egyptian cotton sheets guide.

A few common questions

What is the difference between deep pocket and extra deep pocket sheets?

Deep pocket sheets fit mattresses roughly 13 to 17 inches tall, while extra deep pocket sheets are built for 18 inches and up. Measure your mattress, including any topper, to know which you need.

Will deep pocket sheets fit a normal mattress?

They will, but you may get a little extra fabric to tuck. With 360-degree elastic the sheet still grips a thinner mattress snugly, so a deep pocket set is a safe choice if you are unsure.

Why do my fitted sheets keep popping off?

Almost always because the pocket is too shallow for your mattress, or the elastic only runs across the corners. A deeper pocket with all-around elastic solves both problems.

How do I measure mattress depth for sheets?

Stand a tape measure against the side, measure from the bottom seam to the top seam, add any topper thickness, then add about 2 inches. Match that number to the pocket depth on the label.