I ordered 5 pillow inserts. The 28x28 were perfect for my 26x26 pillow shams. These 16x16 were way too small for my 15x15 pillow covers. They were 16 if you stretch the pillow as much as you can but the body of the pillow was more like 13x13. Sadly, I had to return them and it costs $8 dollars to return them, so that is somewhat of a deterrent to ordering more.