An Overview of Leather Thicknesses

Ounces	Irons	Fractional Inches	Decimal Inches	Millimeters	Application
One ounce of leather is equal to 1/64" in thickness, but hides rarely measure to the exact 1/64" throughout, as there are always slight variations in thickness. Hides run through a splitting machine are more consistent, but still not perfect. It is best to remember that the more ounces there are, the heavier the leather will be. The chart below provides basic leather conversions and the uses of each size.
1 oz. leather	0.75	1/64	0.016	0.41 mm	Linings, Shoes, Boots, Pouches, Purses, Gussets, and Garments
2 oz. leather	1.50	1/32	0.031	0.78 mm
3 oz. leather	2.25	3/64	0.047	1.19 mm
4 oz. leather	3.00	1/16	0.063	1.60 mm	Purses, Shoes, Boots, Pouches, Aprons, Chaps and Knife Sheaths
5 oz. leather	3.75	5/64	0.078	1.98 mm
6 oz. leather	4.50	3/32	0.094	2.39 mm
7 oz. leather	5.25	7/64	0.109	2.78 mm
8 oz. leather	6.00	1/8	0.125	3.18 mm	Belts, Saddlebags, Bridles, Halters, Dog Collars, Straps, Scabbards, Holsters, Sheaths, Tool Pouches and Slings
9 oz. leather	6.75	9/64	0.141	3.58 mm
10 oz. leather	7.50	5/32	0.156	3.96 mm	Heavy Belts and Strap Goods, Gun Belts, Stirrup Straps, Cattle Halters, Heavy Horse Halters and Leads
11 oz. leather	8.25	11/64	0.172	4.37 mm
12 oz. leather	9.00	3/16	0.188	4.78 mm
13 oz. leather	9.75	13/64	0.203	5.17 mm
14 oz. leather	10.50	7/32	0.219	5.57 mm	Safety Belts*, Harnesses, Stirrup Straps, Saddle Skirting, Soles and Heels, Gunbelts and Machine Belting
15 oz. leather	11.25	15/64	0.234	5.95 mm
16 oz. leather	12.00	1/4	0.250	6.36 mm	Safety Harnesses, Work Harnesses, Saddle Skirting, Soles and Heels
*Always remember that leather is a natural material that’s not intended for use on products that carry a high liability or certification of tensile strength. On occasion, leather fibers can become weak without any visible signs of wear. Fall arrest or safety equipment should never be made with leather constructing the strength member. More consistent materials like heavy-duty webbing should be used for strength member construction.