Measure your bed first. The size of your bed is important to note but more specifically you need to measure the depth of your bed to find the right mattress pad. A standard mattress is seven to nine inches deep, a pillow top mattress is usually 10 to 15 inches deep and an extra deep mattress is 15 to 22 inches deep.
Factor in standard mattress pad sizing. Standard mattress pads are seven to 15 inches deep, whereas an extra deep pad can go up to 22 inches deep. This is important to consider when you think about what kind of sheets you might need to buy to account for the added depth of mattress pad if you already have a deep mattress.
Decide which type of mattress pad you need. Buy according to material first, thickness second, fastener third. Mattress pads are made with a variety of materials including cotton, wool, silk, polyester, organic cotton, foam, feathers, synthetic down and even vinyl. Buy the thickest mattress pad in your price range, as it'll essentially be priced by the thickness.
Consider the type of fastener that will be most secure on your mattress. There are four types of mattress pad: the wrap pad, anchor pad, fitted pad and the "guaranteed to fit" mattress pad. Anchor pads cover the top of the mattress and are "anchored" by elastic bands in the corner and though cost effective tend to shift on the bed. A fitted pad is much like a fitted sheet, a wrap pad is quilted on the top and sides and has elastic all the way around which ensures a secure fit and the guaranteed to fit pad is great for deep mattresses because it has expandable sidewalls.
Spring for a heated mattress pad to relieve muscle and joint pain or a hypoallergenic mattress pad to resist dust mites.