StitchMath
Leatherworker laying out patterns on cognac leather at a warm workshop bench
The leatherworker’s reference desk

Leathercraft, minus the guesswork

Free calculators and honest buying guides for people teaching themselves leatherwork. Work out your stitch pitch, how much leather to buy and the right thread — then see exactly which tool fits.

Try the stitch calculatorStart with the guides
7 free calculators 45+ guides & comparisons No sign-ups, no fluff
Measure twice, buy once

Calculators

Every tool renders its answer on the server — bookmarkable, shareable and fully working without JavaScript.

Stitch Pitch Convertermm ↔ SPI, plus the right thread and irons for your pitch.Leather Project CalculatorSquare feet, hide cut and thickness for wallets, belts and bags.Thread Length EstimatorExactly how much thread to cut so you never run short mid-seam.Thickness ConverterTurn leather ounces into real millimetres and inches.Belt Length CalculatorBelt size, strap blank length and hole layout.Rivet Length SelectorThe right rivet or Chicago screw for your leather stack.Needle & Thread SelectorMatch needles to thread in mm, Tex or by pitch.
Leathercraft tools laid out on a dark cutting mat: pricking irons, skiving knife, mallet and awls
Buy fewer, better tools

Skip the beginner kit

All-in-one kits pad the box with tools you will replace within a month. Our buying guides walk you through the short list worth owning — the essential first tools, the right pricking irons, a proper cutting knife — and the head-to-head comparisons settle the classic debates.

Browse best-gear guides
Learn the craft

Start here: popular guides & comparisons

GuideEssential leather tools for beginnersGuideLeather weight chart: oz to mm buying guideHow-toHow to saddle stitch leather (step by step)ComparePricking irons vs stitching chiselsBestBest pricking irons for beginnersGuideLeathercraft glossary: 25 terms explained
Our promise

Why StitchMath

1

Tool-first, not blog-first

Every answer starts with a working calculator or a real chart — not 1,500 words before the point.

2

Honest about specs

We flag where sellers measure pitch differently and where leather thickness is only a range, so you buy the right thing once.

3

US units, mm too

Inches, feet and ounces first, with millimetres alongside — the way US makers actually work.