Pleating Calculator (Skirts, Curtains, Etc!)

**Welcome! I hope you find this pleating calculator useful! Please note, when you are pleating fabric, especially thick fabric, you will need to account for a bit of extra length that gets “eaten up” in the folds. I recommend sewing a practice item first, and using a bit more length than needed and adjusting it as needed for the final fit. Use these calculators as a guide, not as gospel! And remember to always add seam allowance, it is not included here! ** More Disclaimers here

Basic Pleat Calculator

Basic Pleat Calculator

Enter two values to calculate the third.

Basic Pleat Calculator

The knife pleats in this calculation have no gaps in between, and no overlapping.

Use this calculator to figure out:

  • The length of fabric you will need based on how many pleats you want, and how wide you want your pleats to be
    or:
  • The maximum number of pleats you can fit on a given length of fabric, depending on how wide they ought to be
    or:
  • The largest width of pleats you can make based on how long your fabric is, and how many pleats you want to fit on it
  • In addition, if you want to figure out how many pleats of what size you can make to end up with a certain finished length of pleated fabric, I will show you the formula below!

One box pleat equals two knife pleats, but with one pleat alternating directions.

Table Of Contents
Pleating Calculation Examples
How Much Fabric Will I Need?
How Many Pleats Can I Fit On My Fabric?
How Big Can I Make My Pleats?
How Can I Solve For A Specified Finished Pleated Length?

Pleating Calculation Examples

How Much Fabric Will I Need?

If you have an idea of how many pleats you want, and how wide you want them to be, then you can figure out how much fabric you will need.

For example, if I want to make 4, 1 inch wide pleats, then I will need a piece of fabric that is at least 12 inches long.

pleat calculator example

How Many Pleats Can I Fit On My Fabric?

If you already have a piece of fabric you want to pleat, and you know how wide you want your pleats to be, you can use the pleating calculator to figure out how many of those size of pleats you can fit on it.

For example, I have a piece of fabric that is 24 inches long, and I want my pleats to be 2 inches wide. I would enter these numbers into the calculator to find the result of 4 total pleats that will fit on the fabric.

When I tried this in real life, it was accurate. I could fit 4 whole pleats with some material left over.

How Big Can I Make My Pleats?

If you have a length of fabric and you already know how many pleats you want to fit on it, you can enter those numbers to determine the maximum size of pleats you can make that will fit on the fabric.

For example, if I want to fit 2 whole pleats on a 24 inch long piece of fabric, I have to make my pleats 4 inches or smaller, but there will be a bit of fabric left over.

(Since each whole pleat has three layers of fabric. If you make the middle layer smaller than the top layer of the pleat, you will be able to fit more on, but that is beyond the scope of this basic calculator.)

How Can I Solve For A Specified Finished Pleated Length?

If you want to make a skirt, for example, and you have a specified finished length you need the pleated fabric to end up (remember to add seam allowance!), here is the formula to figure it out!

First, you will multiply the desired finished length by 3, to find the fabric length.

For example, if my desired finished length is 30, then the fabric length needs to be 90.

Then, once you have the fabric length, you can plug that number into the calculator to figure out the best number and sizes of pleats you can fit on it. using multiples will help you get a whole number of pleats with no space left over!

In my example below, My desired finish length of 30 was multiplied by 3 to find the fabric length of 90. Then, I entered a pleat width of 2 inches to figure out that I can fit 15 pleats.

Then I would need to add a seam allowance and a bit extra just in case, so perhaps I would cut a 95-100 inch long piece of fabric to start with.

For more in depth information about the wonderful mathematics behind pleats, I highly recommend you check out this amazing resource from craftematics!

Also be sure to check out my other free sewing calculators here!