Stitching Hole Spacing Calculator

Calculate the number of stitching holes and optimal spacing for leather seams. Enter seam length, pricking iron spacing, and desired stitches per inch.

Inputs

Seam Length

Pricking Iron Spacing

Target Stitches Per Inch

Tab to move between fields

Results

Total Holes

Effective SPI

6.4 stitches/in

Actual Spacing3.96 mm

Seam Length304.8 mm

Total Stitches78

How to Use This Calculator

Enter the seam length in inches to be stitched.
Set the stitch spacing in stitches per inch (5-7 SPI for saddle stitch).
Review the total number of stitching holes to punch.
Use a pricking iron or stitching chisel matching your SPI to punch the holes.
Mark the seam line with a wing divider at the appropriate distance from the edge before punching.

How the result changes with Seam Length

Seam Length	Total Holes	Effective SPI
12	78	6.4 stitches/in
42	268	6.4 stitches/in
78	497	6.4 stitches/in
108	687	6.4 stitches/in

What each input means

Seam Length: Total length of the seam to be stitched in inches
Pricking Iron Spacing: Distance between prongs on your pricking iron (common: 3mm, 4mm, 5mm)
Target Stitches Per Inch: Desired stitch density (5-7 typical for most leather projects)

How this is calculated

Worked example, using the default values

Identify Input Parameters
Seam Length = 12, Pricking Iron Spacing = 4, Target Stitches Per Inch = 7 = 3 input(s) provided
Calculate Total Holes
Total Holes
78 = 78
Calculate Effective SPI
Effective SPI
6.4 = 6.4
Calculate Actual Spacing
Actual Spacing
3.96 = 3.96
Calculate Seam Length
Seam Length
304.8 = 304.8

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