Before you buy fitted sheets, it is essential to measure your mattress accurately to ensure a snug, secure fit. A ill-fitting sheet can come undone mid-sleep, create annoying wrinkles, or fail to cover the entire surface, which can interfere with rest and cause premature wear on your mattress. Start by stripping the mattress completely so you can measure the original mattress profile. Use a flexible fabric tape, never a hard plastic ruler, because it will adapt to the contours of the mattress.

First, measure the longest side of the mattress from the head end to the foot end. Then measure the width from one side to the other. These dimensions often match common mattress dimensions like twin, full, queen, or king, but mattress sizes can vary slightly, so always measure yourself. Next, measure the thickness of the mattress by placing the tape at the foundation level and extending it perpendicularly to the top surface. This is critical because deep mattresses, روتختی تشک طبی especially those with plush pillow tops, can be as tall as 16 inches. Most standard fitted sheets are designed for mattresses up to 14–16 inches in height, but if yours is deeper, you’ll need extra-deep sheets.

Don’t forget to inspect the corners. Some mattresses feature contoured corners, especially if they are luxury models. If the corners are not square, document the contour so you can select a fitted sheet with a flexible hem capable of securing uneven edges. Also, consider the topper material. If your mattress includes a removable topper, measure with those layers in place since they significantly affect fit.

Once you have all three measurements—height, width, and length—note them on paper. Cross-reference with the product details listed by the retailer. Many brands state the deepest fit, so verify your numbers fall below the maximum. If your mattress is right at the cutoff, it’s strongly recommended to pick a sheet rated for a higher capacity. Finally, check customer reviews for insights on fit and elasticity, especially if you’re shopping remotely. Taking the time to measure thoroughly will prevent returns and deliver restful nights every time.