Leather Thickness and Conversion Chart

How is leather thickness measured?

Leather thickness is typically measured in ounces. This unit of measurement does not convey weight in the colloquial sense, but rather the thickness. And since it is critical to have the necessary thickness of leather for a particular project, it is therefore also critical to know ounce measurements.

Gauging Leather Thickness
A leatherworker gauging the thickness of leather.
Leather Thickness Gauge
A device used to measure leather thickness.

So how thick is each ounce of leather?

An ounce of leather equals 1/64 of an inch. So, 9 ounces are equal to 9/64 of an inch and so on. For further assistance, here is a leather thickness chart for quick and easy conversions. Bear in mind, a piece of leather will have slightly variable thickness, so our chart reflects that.

Ounce Thickness Inch Thickness Millimeter Thickness
2 – 3 oz 1/32 – 3/64 in .8 – 1.2 mm
3 – 4 oz 3/64 – 1/16 1.2 – 1.6 mm
4 – 5 oz 1/16 – 5/64 in 1.6 – 2.0 mm
5 – 6 oz 5/64 – 3/32 in 2.0 – 2.4 mm
6 – 7 oz 3/32 – 7/64 in 2.4 – 2.8 mm
7 – 8 oz 7/64 – 1/8 in 2.8 – 3.2 mm
8 – 9 oz 1/8 – 9/64 in 3.2 – 3.6 mm
9 – 10 oz 9/64 – 5/32 in 3.6 – 4.0 mm
10 – 11 oz 5/32 – 11/64 in 4.0 – 4.4 mm

So what thickness of leather do I need?

As mentioned before, it is essential that you get the right thickness of leather for your project. Some variance is allowed for personal taste, but the chart below is a good guide to give you an idea of what you may need.

And remember, it is just as vital to know what tannage of leather you need as well as the thickness. For most bags, chaps and moccasins you will want chrome tanned leather. And for belts, knife sheaths and holsters, you’ll want to use vegetable tanned leather.

Ounce Thickness Common Projects
2 – 3 oz lining, embossing
3 – 4 oz lining, embossing, light bags, light wallets
4 – 5 oz wallets, bags, chaps
5 – 6 oz phone and tablet cases, book covers, light moccasins, chaps
6 – 7 oz heavy cases, covers, chaps, moccasins
7 – 8 oz moccasins, light sheaths, light holsters, belts
8 – 9 oz standard belts, standard sheaths, straps, medium holsters
9 – 10 oz heavy holsters, heavy belts, light armor
10 – 11 oz heavy straps, medium armor