Leather Thickness Converter (oz ↔ mm ↔ in)
Translate leather weight in ounces to real thickness in millimetres and inches.
Quick answer
Leather thickness is sold by weight in ounces: 1 oz equals 1/64 inch, which is about 0.4 mm. So 4 oz ≈ 1.6 mm, 8 oz ≈ 3.2 mm. Enter a value in ounces, millimetres or inches to convert instantly and see what that weight is typically used for.
5 oz = 2 mm
The one number to remember
US leather is graded by weight, where one ounce equals one-sixty-fourth of an inch of thickness — almost exactly 0.4 mm. Multiply the ounce figure by 0.4 to get millimetres, or by 1/64 to get inches. Because it is a nominal grade, a hide sold as “5–6 oz” can measure anywhere across that band, so treat the number as a target, not a guarantee.
Leather weight chart
| Weight | mm | inch | Typical uses |
|---|---|---|---|
| 1 oz | 0.4 mm | 0.016" | Linings, very fine work, bookbinding overlays |
| 2 oz | 0.8 mm | 0.031" | Wallet interiors, card slots, linings, garment trim |
| 3 oz | 1.2 mm | 0.047" | Wallet interiors and exteriors, watch straps, small goods |
| 4 oz | 1.6 mm | 0.063" | Bag panels, wallet exteriors, light straps, tooling practice |
| 5 oz | 2.0 mm | 0.078" | Bags, structured wallets, notebook covers, moderate tooling |
| 6 oz | 2.4 mm | 0.094" | Bags, journal covers, key fobs, firmer small goods |
| 7 oz | 2.8 mm | 0.109" | Light belts, straps, bag bottoms, sheaths |
| 8 oz | 3.2 mm | 0.125" | Belts, straps, dog collars, knife sheaths |
| 9 oz | 3.6 mm | 0.141" | Belts, holsters, heavy straps |
| 10 oz | 4.0 mm | 0.156" | Belts, holsters, weight-lifting belts, tack |
| 11 oz | 4.4 mm | 0.172" | Heavy belts, holsters, saddlery |
| 12 oz | 4.8 mm | 0.188" | Heavy-duty straps, holsters, gun belts |
| 13 oz | 5.2 mm | 0.203" | Heavy tack, holsters, industrial straps |
| 14 oz | 5.6 mm | 0.219" | Very heavy tack and harness work |
Frequently asked questions
How thick is 4 oz leather?
About 1.6 mm, or 1/16 inch. Each ounce of leather weight equals roughly 0.4 mm (1/64 inch), so 4 oz ≈ 1.6 mm.
How many mm is 8 oz leather?
8 oz leather is about 3.2 mm thick — a typical weight for belts and straps.
Why is leather measured in ounces?
It is a thickness convention, not a true weight: 1 oz means the leather weighs one ounce per square foot, which corresponds to about 1/64 inch of thickness.
Is leather thickness exact?
No. Hides vary, so sellers quote a range like 4–5 oz. For belts and anything load-bearing, confirm the exact thickness with the seller.