How to Measure Your Mattress Before Buying Sheets

A mattress-size name is helpful, but it is not enough to guarantee a fitted sheet will fit. Mattress dimensions, toppers, and pocket depths vary, so a few quick measurements can prevent a frustrating mismatch.

What you need

Use a flexible tape measure and remove loose bedding. Leave any mattress protector or topper in place if you plan to use it under the fitted sheet.

1. Measure the width

Measure straight across the widest part of the mattress from one side edge to the other. Keep the tape level rather than following the curve of the surface.

2. Measure the length

Measure from the head of the mattress to the foot. Do not include the bed frame, headboard, or decorative upholstery.

3. Measure the total depth

Measure from the bottom edge of the mattress to the highest point of the sleep surface. Include any topper that will remain on the bed. This measurement is especially important for deep-pocket fitted sheets.

4. Compare actual dimensions

Match your measurements with the dimensions and pocket depth listed on the product page. International labels such as Double, King, Super King, or Mega King may not match common U.S. dimensions, so rely on the numbers rather than the name.

5. Check the set contents

A sheet set may include a flat sheet, fitted sheet, and one or more pillowcases, but contents vary. Some products include only a fitted sheet or use pillow sizes that differ from your current pillows.

Helpful fitting notes

• A pocket that is too shallow may pull off the corners.
• A pocket that is much deeper than the mattress can leave extra fabric unless the elastic is designed to manage it.
• Rounded corners, thick toppers, and adjustable-bed movement can affect fit.
• Wash and dry only as directed because excessive heat can change the dimensions of some fabrics.

Taking these measurements once and saving them in your phone makes future bedding purchases much easier.