How much leather does this pattern really take?
Your parts summed to square feet with the waste hides genuinely have, how many sides that is, what it costs at your price — and the 1 oz = 1/64" thickness rule, exact. Everything stays in your browser.
The parts
The numbers here are yours to check. This page does arithmetic on what you type — it cannot see your recipe, your equipment or your batch.
Want it to remember?
In MadeKeeper the sides are inventory by the square foot: every piece consumes its pattern plus your real waste, and the wallet knows what the leather in it cost — which is what the price stands on. See for leatherworkers or poke around the live demo. $19/mo for the whole back office, kept for as long as you stay. The shop stays free for cost a piece and one fair — no product cap. The tax packet, Etsy and Square, and more fairs are the $19.
Pattern to hide, honestly
Leather is bought by the square foot and lost to the parts of the animal that lived hardest. The math below is the same math the calculator runs — waste honest, thickness exact.
Why so much waste on a hide?
Because a hide was an animal. Brands, scars, holes, and the stretchy belly all get cut around; the tight, structural leather lives along the back. Twenty percent waste is a working default for ordinary projects — belts cut along the spine waste less, big clean panels from a scarred side waste far more. Your own cutting history is the number; the default just starts you honest.
What do the oz numbers actually mean?
Thickness, by the trade rule: one ounce is 1/64 of an inch, exactly 0.397 mm. So 8-9 oz belt leather is about 3.2-3.6 mm; 2-3 oz lining runs around a millimeter. It reads like weight because it once was — a square foot of 1 oz leather weighs about an ounce — but the number on the tag is thickness, and the conversion is settled, not contested.
How big is a side?
Whatever the tag says — commonly 18-25 square feet for a cow side, which is why the hide size is your input rather than our assumption. A double shoulder or a belly runs far smaller and yields differently. Enter the size of what you actually buy, and the hides-to-buy count ceilings honestly — a project that needs 1.1 sides needs 2 sides.
Should I buy the whole project from one hide?
When color and temper matter, yes. Two veg-tan sides from the same tannery will drink dye differently and burnish differently — a bag with panels from two hides can show it. The count on this page tells you if the project FITS one side; whether it should is craft judgment, and the answer for matched work is usually yes, with room.