What Is a Size 18 in Inches?

Arm length varies for size 18 garments depending upon the fit. For petite styles, the length is 31 1/8 inches. Tall tops have sleeves that run 33 3/8 inches. Regular fit sleeves are 32 3/8 inches long. According to Discovery, size measurements often vary among manufacturers and are constantly changing. To attract customers, manufacturers lower sizes. For instance, in 1997, a size 8 was the same as a size 10 was a decade before.