Mattress Topper Size Guide: How to Pick Twin, Queen, King, or California King

Toppers are sized to match standard US mattress dimensions, not the frame or the comforter you already own. If you know your mattress is a Queen, you want a Queen topper. Simple enough, but it is worth confirming with a tape measure rather than assuming, especially with older or imported mattresses that may not follow the exact standard.

The ECOFORMERS Bamboo Mattress Topper comes in four sizes with these approximate dimensions: Twin 39 by 75 in, Queen 60 by 80 in, King 76 by 80 in, and California King 72 by 84 in. Notice that King and California King are not interchangeable. King is wider and shorter, while California King is narrower and longer. Mixing these up is one of the most common ordering mistakes, so double-check which one your mattress actually is.

Deep pocket refers to how tall a mattress the topper's skirt can wrap around and hold onto. The ECOFORMERS topper uses a 360-degree elastic deep-pocket skirt that fits mattresses roughly 8 to 20 in deep. That range covers most modern setups, including thicker foam and hybrid mattresses, and it also accounts for the extra height when you have a mattress plus a separate pillow top or protector.

The reason this matters is fit and stability. A skirt that is too shallow will pop off the corners every time you move, while the elastic-all-around design grips the sides so the topper stays flat and centered through the night. If your mattress falls inside that 8 to 20 in window, the topper should seat securely. If your mattress is unusually thin or unusually tall, measure carefully before ordering.

You only need three measurements: length, width, and depth. For length and width, run a tape measure across the bare mattress from seam to seam, without sheets or a protector in the way. Compare those numbers to the size chart above to confirm whether you have a Twin, Queen, King, or California King.

Depth is the measurement people forget. Stand the tape vertically at the side of the mattress and measure from the bottom edge to the top surface. Include anything permanently attached, like a built-in pillow top, but you do not need to add a thin fitted sheet. As long as that depth lands between 8 and 20 in, the deep-pocket skirt will have room to grip. Write all three numbers down before you order so you are not measuring from memory.

The ECOFORMERS topper is a soft quilted comfort layer with a breathable, noiseless surface, so it adds a plush feel without the crinkle some toppers have. The surface is a soft quilted bamboo-style fabric. A quick note on naming: this is a bamboo-style, bamboo-blend feel rather than a claim of 100 percent bamboo, and the exact fiber content and thickness are not something we list, so treat the feel as the selling point rather than a spec sheet.

It is machine washable and ships with a reusable storage bag, which is handy for guest-room setups or seasonal swaps. To install, pull the elastic skirt over all four corners the way you would a deep fitted sheet, then smooth the quilted surface flat. For anything beyond size, fiber, and care details, check the product page rather than relying on assumptions.

Confirm your mattress size by measuring length and width, then match it to Twin, Queen, King, or California King. Remember that King and California King differ, so pick based on your actual mattress rather than the label on an old sheet set.

Measure your mattress depth and confirm it sits between 8 and 20 in so the deep-pocket skirt fits. If you check both boxes, you can order with confidence, and free US shipping means there is no size-based surcharge to factor in.