Mattresses come in various depths, ranging from 7 to 25 inches. With the vast array of mattress options available today, there are also many options to choose from when selecting sheets. Finding sheets to fit your mattress is easy once you've determined the mattress depth. Sheet packages feature product information, which is where you will find out what size and height of mattress the fitted sheet will fit best.
Ask the salesperson selling you the mattress when you purchase a new mattress. He should be able to let you know how deep your mattress is.
Look at the the paperwork you received when you purchased your mattress. The depth of the mattress may be listed in the specification information.
Measure the height of the side of the mattress using a ruler, yardstick or tape measure.
Decide what kind of sheets you would like, including the color and thread count.
Look at the package of sheets to learn the depth of mattress the fitted sheet will fit. Most packages today will inform you of this.
Take a look at the product specification or product description if you are shopping online. This area will likely include mattress depth information for the sheets you are considering.