Metric Conversion From US Stitches Per Inch

Stitches Per InchAll of the sewing machines that I have seen that were made in the last 10 or 15 years have stitch length settings that are in millimeters. Back when sewing machines were still being made in the US, most of our sewing machines had stitch length settings that were in stitches per inch. The picture to the right shows the stitch length knob of an old Singer sewing machine model 750.

Most of the world uses the metric system, and it probably won’t be long before the US does too. For now, if you don’t want to learn the metric system, you can simply do a little math to convert the number of stitches per inch that you desire to the metric equivalent used by your sewing machine.

While browsing the Janome Forum this morning, I saw that a forum member had asked how to convert the metric stitches to stitches per inch. It’s a really easy conversion to do, and you can do it with a calculator.

25.4 / X = Y

In English that equation reads, “25.4 divided by X equals Y”. X is the number of stitches per inch you want, and Y is the setting in millimeters for your sewing machine. You will probably have to round your answer to the nearest tenth of a millimeter, because sewing machines don’t have higher accuracy than that. In some cases, your sewing machine may only increment it’s stitch length setting in half millimeters, so you would round up or down as needed.

Stitches Per Inch Metric Equivalent (mm) Metric Stitch Length (rounded)
15 1.6933333 1.7
12 2.1166666 2.1
10 2.54 2.5
9 2.8222222 2.8
8 3.175 3.2
7 3.6285714 3.6
6 4.2333333 4.2
5 5.08 5

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Reader Comments (4)

Amanda Mitchell on 5/28/11 @ 1:43pm

THANKS BRIAN!!!!! Have a great day in church tomorrow!!!!

b.gottier on 5/28/11 @ 2:33pm

Amanda, glad you found this useful. Sunday is my only day off, so I always have a great day, and I always go to church. We usually go to Calvary Chapel Bible Fellowship, which is here in Temecula.

Mary Hackett on 9/12/13 @ 3:18pm

Oh, you are a lifesaver! got a new machine and could not figure out the stitch lengths. I am so grateful you took the time to post this.

amy on 6/10/16 @ 12:05pm

Wonderful! I wrote the chart on the cover of my manual so I'll always be able to see it! I was raised using stitches per inch and have a hard time making the jump to metric on my new machine. Thank you!

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