Leather Weight Chart: Ounces to Millimeters
Leather is sold by weight, not thickness — but 1 oz roughly equals 1/64 inch (about 0.4 mm), so the math is simpler than it sounds.
Quick answer
Leather "weight" is a thickness measurement: 1 ounce equals about 1/64 inch, or roughly 0.4 mm. So 4 oz leather is about 1.6 mm, 5 oz is about 2.0 mm, 8 oz is about 3.2 mm, and 10 oz is about 4.0 mm. Because hides vary, most leather is sold in a range like 5–6 oz. Pick thinner weights for wallets and linings, thicker for belts and holsters.
Here is the quirk that trips up every beginner: leather thickness is measured in ounces. An ounce doesn't describe how heavy your piece is — it's shorthand for how thick it is. One ounce of weight corresponds to about 1/64 of an inch of thickness, which works out to roughly 0.4 mm. Stack those up and the numbers get easy: 4 oz is about 1.6 mm, 8 oz is about 3.2 mm, and so on.
This page explains what the ounce measurement really means, how to read a weight range, why two pieces of "6 oz" leather can feel different, and which weights to reach for on common beginner projects. The full conversion chart sits just below. When you need an exact number in either direction, use our leather thickness converter.
What does "ounce" actually mean for leather?
The ounce figure comes from an old trade convention: a piece of leather 1/64 inch thick weighs about one ounce per square foot. So instead of quoting thickness in fractions of an inch, tanneries quote it in ounces. It's a thickness label wearing a weight costume.
The clean rule to memorize: 1 oz ≈ 1/64 in ≈ 0.4 mm. Multiply from there. Two ounces is about 0.8 mm, three is about 1.2 mm, and each additional ounce adds roughly another 0.4 mm. It's an approximation — real hides don't land on perfect gridlines — but it's accurate enough to choose leather with confidence.
How to read a weight range like 5–6 oz
Leather is almost always sold as a range, not a single number: 4–5 oz, 5–6 oz, 8–9 oz. That range exists because a single hide is not uniform. The leather is thicker over the back and thinner toward the belly and legs, and tanning doesn't flatten every fiber to an identical gauge.
Read the range as "somewhere between these two thicknesses." A 5–6 oz side means most of it measures roughly 2.0–2.4 mm. If your project needs a precise, consistent thickness, buy a hair heavier than your target and have it split or skived down, or measure with calipers and cut your parts from the most even area. Don't assume every square inch matches the label.
Why two pieces of the same weight feel different
Weight tells you thickness, not stiffness or density. A 5–6 oz veg-tan bridle is firm and holds a fold crisply; a 5–6 oz chrome-tanned garment leather at the same thickness drapes and flops. Tannage, temper (soft vs. firm), and where the piece was cut from the hide all change how it behaves.
So use the weight chart to get in the right thickness neighborhood, then judge temper by hand or by description. For tooling and stamping you also want the right leather, not just the right number — see our picks for veg-tan leather for tooling and our guide to hide cuts for why location on the hide matters.
Which weight for wallets, bags, belts, and holsters
Matching weight to project is most of the battle. Rough starting points for beginners:
- Wallet interiors, card pockets, linings: 2–3 oz (0.8–1.2 mm). Thin enough to fold and layer without turning the wallet into a brick.
- Wallet exteriors, small pouches: 3–4 oz (1.2–1.6 mm).
- Bags and totes: 4–6 oz (1.6–2.4 mm) for structure; heavier for the base, lighter for gussets.
- Belts, straps, dog collars: 8–10 oz (3.2–4.0 mm). This is the classic belt range.
- Holsters, knife sheaths, heavy work: 7–9 oz (2.8–3.6 mm), sometimes doubled.
When you need to estimate how much leather to buy for a build, our leather project calculator helps you plan area and offcuts.
How weight affects tooling and folding
Thickness changes what the leather can do. Thin leather (2–3 oz) folds cleanly and takes tight bends, which is exactly what wallet interiors need — but it's too shallow to carry deep tooling. Heavier leather (6 oz and up) holds crisp stamped and carved detail because there's enough depth for the impression, but it fights you when you try to fold it and usually needs to be skived, glued, or stitched rather than bent.
If a design has to both fold and look structured, drop to a lighter weight and reinforce it, or skive the fold line so it bends where you want. Thickness also drives your hardware and needle choices, and how thick a stack your hole punch or irons have to clear.
Leather weight to thickness chart
| Weight | Thickness (mm) | Thickness (in) | 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 |
Key takeaways
- 1 oz ≈ 1/64 in ≈ 0.4 mm. Multiply ounces by 0.4 to get millimeters — close enough for buying decisions.
- Ranges exist because hides vary in thickness across the back, belly, and legs; the label is an average, not a guarantee.
- Weight ≠ stiffness. Two pieces at the same oz can drape or stand up depending on tannage and temper.
- Thin folds, thick tools. Use 2–4 oz for wallets, 8–10 oz for belts, and reach for the converter when in doubt.
Frequently asked questions
How thick is 4 oz leather in mm?
About 1.6 mm, or roughly 1/16 inch. Since 1 oz is about 0.4 mm, 4 oz lands near 1.6 mm. It's a light-to-medium weight, good for wallet exteriors, small pouches, and lightweight bag panels. For exact figures either direction, use the leather thickness converter.
How many mm is 8 oz leather?
Roughly 3.2 mm, or about 1/8 inch. Eight-ounce leather is firm and substantial — a common weight for belts, straps, and holster bodies. Remember it's usually sold as a range like 7–8 or 8–9 oz, so measure with calipers if you need a precise thickness.
What is 5 oz leather in mm?
About 2.0 mm, or close to 5/64 inch. Five-ounce leather is a versatile middle weight that works for bag bodies, straps, larger wallets, and light structural pieces. It folds with some persuasion and holds moderate tooling.
How thick is 10 oz leather?
Around 4.0 mm, or roughly 5/32 inch. Ten-ounce is heavy, stiff leather used for thick belts, heavy straps, and rugged sheaths. It does not fold easily and is usually skived at any bend. If your project needs to bend, consider a lighter weight instead.
What leather thickness is best for wallets?
Use 2–3 oz (about 0.8–1.2 mm) for interiors, card slots, and linings so the wallet stays slim, and 3–4 oz (about 1.2–1.6 mm) for exteriors. Thin leather folds cleanly and layers without bulk, which is exactly what a good wallet needs.
What weight leather should I use for a belt?
Most belts use 8–10 oz leather (about 3.2–4.0 mm) so the strap is firm and durable without curling. Lighter than 8 oz can feel floppy; heavier than 10 oz gets stiff and hard to buckle. Firm veg-tan in this range is the classic choice.
Last verified 2026-07-14.