How to Calculate Sewing Time By Using Machine RPM?

How to Calculate Sewing Time By Using Machine RPM?

Sewing time calculation is an important matter in readymade garments sector. It’s not a tough task that we have normally seemed. As its importance in garments manufacturing, today I will present here an easy method for calculating sewing time by using machine RPM (Revolution per minute).

Method of Sewing Time Calculation by Using Machine RPM:

Before calculating garments sewing times by using machine RPM (Revolution per minute), an industrial engineer should confirm about the below points:

  1. Stitch per inch (SPI) of the garments,
  2. Seam length in inch of the garments,
  3. Sewing machine RPM (Revolution per minute).

Now by using the below formula, an industrial engineer can easily calculate the required garments sewing times from machine RPM (revolution per minute).

Machine cycle time or sewing times (in second),

Now, I will present here an example to clear all the confusions from the above discussions.


Suppose, for a lock stitch sewing machine, machine RPM is 1500. How much time needed to sew a 40” super imposed seam, where stitch per inch (SPI) is 10?



Sewing machine RPM= 1500,
Seam length in inch= 40”,
Stitch per inch (SPI) = 10.


Machine cycle times or sewing times (in second),

= 16sec.

So, machine cycle times or sewing times is 16sec.

Note: During 16sec sewing time, no machine stopping occurred and this time is calculated by ignoring all the other factors.

Speech from the writer:
If you read this article with full concentration then you can easily answer the below questions in the interview:

  1. How to estimate sewing times by machine RPM?
  2. How to determine sewing machine times by using machine RPM?
  3. Mention an easy method for calculating sewing machine times from machine RPM?
  4. Show a sewing time calculation method by using sewing machine RPM followed in industrial engineering.

Written By-

Mayedul Islam
Merchandiser at Fashion Xpress Buying House.
Badda, Dhaka, Bangladesh.

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Mayedul Islam

Mayedul Islam is working as a Sr. Merchandiser in a reputed Buying House. He has great passion in writing different articles on textile and Garments specially on Merchandising and Garment Washing. Send


  • misganaw

    I would like to give a special thanks

  • Joy banerjee

    Sorry, this is not the formula, as per gsd MST is
    MST = Stitches per cm (SPC or ST/CM)
    RPM x 0.0006 minutes
    The Minimum Sewing Time (MST), that is the fastest possible time to sew one centimeter on that machine, at that speed and stitch density.

  • Md. Saifur Rahman (Kiron)

    Revolution per minute of a Sewing machine = How many stitch that machine can do per minute

    Am I correct on above ?

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