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How much thread for a saddle stitch
The saddle stitch uses two needles, one on each end of a single length of thread, passing both through every hole. That means the thread has to span the whole seam more than once — so the strip you cut is several times the length of the stitch line. Running short near the end is the classic beginner mistake, and it's avoidable with a simple rule.
The rule of thumb
A widely used starting point is the length of the stitch line multiplied by about four to five, plus a few inches at each end for starting, finishing, and threading the needles:
Thread ≈ (Stitch length × 4–5) + tails
For a 6-inch seam, that's roughly 24–30 inches of thread plus tails — call it a comfortable yard. It feels generous, and a little waste is far cheaper than re-starting a seam.
Why the multiplier isn't fixed
Two things push the multiplier up:
| Factor | Effect on thread used |
|---|---|
| Thicker leather | Each stitch travels farther through the material — more thread per hole |
| Higher SPI | More stitches per inch — more passes over the same length |
| Thicker thread / casting | Takes up more length per stitch |
So a thick belt stitched at low SPI and a thin wallet stitched at high SPI can need similar multipliers for different reasons. When in doubt, round up.
Stohlman's classic guidance in The Art of Hand Sewing Leather is to err long — the cost of extra thread is trivial next to the time lost splicing in more mid-seam. Most experienced stitchers cut generous and trim the tails.
You'll backstitch two or three holes at the end and need enough to bury or knot the ends. Add several inches beyond the calculated length specifically for that.
Hide measures the thread for your seam
Enter your seam length, SPI, and leather weight and Hide estimates the thread to cut — with the multiplier adjusted for thickness, plus tail allowance. Free to download.
Sources
- Al Stohlman, The Art of Hand Sewing Leather (saddle-stitch method and thread allowance)
- Nigel Armitage saddle-stitch tutorials; practitioner guidance on thread estimation
The multiplier is an estimate — cut generously, especially on thick leather or high SPI.