Common Leather Strap Sizes
Leather straps have standard sizes depending on the strap category. Since most straps are used with metal hardware like buckles, leather straps need to have some standardization in terms of width for them to be compatible with metal hardware.
Watch Strap Sizes
The width of the watch strap is defined by the lug width of the watch. Most watch straps start from 18mm width and can go up to 24mm width. Womens’ watches can be a little narrower than mens’ watches. Apple watches have 22mm and 24mm strap size options.
Belt Strap Sizes
Belt straps can start from 20mm and can go up to 60mm. 20mm is a narrow size for belts and it is mostly used by women. 30mm straps can be used both by men and women. Narrow belts are more suitable for formal occasions. Wider belts are for more casual usage. For example, 40mm width can be used with denims etc. 1/2″, 1”, 1-1/4″, 1-1/2″, 1-3/4″, and 2” are standard belt strap width in inches.
5/8” Leather Strap
5/8” leather strap is a popular width used mostly for dog collars & leads and purse straps.
Others?
Leather straps are usually sold in 12″, 24″, 36″, 48″, 60″, 72″, 84″ and 96″ standard lengths.