Craft & Design
Leather Weight → Thickness
Ounces per square foot to millimeters and inches — plus what projects each weight suits.
Leather Weight → Thickness
Inputs
For multi-unit runs — estimates hides needed
Results
Thickness
0.125 in
3.20 mm
Suitable for
Bag, Belt
Not ideal for
Wallet (2-4 oz) · Watch strap (3-5 oz) · Glove (2-3 oz) · Saddle (12-20 oz)
Hide sides needed
Assumes 25 sq ft per typical side
0.03
How to use this
Leather is sold by weight per square foot — a holdover from hide trade. Each ounce equals 1/64 inch or about 0.4 mm. A 4 oz leather is roughly 1.6 mm; an 8 oz belt blank is about 3.2 mm.
Pick the weight band that matches the project: too thin and a belt stretches into a noodle, too thick and a wallet won’t fold closed. A typical cow side yields 20-25 square feet, so plan for a little waste on curves and edges.
Formula
thickness_mm = weight_oz × 0.4
thickness_in = weight_oz ÷ 64
hides_needed = area_sq_ft ÷ 25
Related calculators
Formula
thickness_mm = weight_oz × 0.4; thickness_in = weight_oz ÷ 64