How to Cut Fabric into Accurate Squares for Quilts (4 Ways)

If you’re about to start your first patchwork quilt, you’ll need to learn how to cut fabric yardage into accurate squares. I’ve described multiple methods based on what tools you have (rotary cutter or scissors), and how many squares you want to cut.

Contents list:

How to prepare fabric for quilting:

The first step for some quilters is to wash their fabric. This is to shrink the fabric before use, stop the dyes from bleeding, and wash out chemicals and dirt. Not all quilters wash their fabrics before use (this is called “pre-washing”). Some people like the crinkled “antique” look that their quilt gets if they wash it after it’s been quilted. Unwashed fabric is also stiffer, making it easier to accurately cut and sew. So it’s a personal choice whether you wash your fabric before use, or after you’ve made your quilt.

If you’re using dark-colored fabrics and are worried about the dye bleeding, you can test it. Cut a small piece and soak it in warm or hot water for about 20 minutes. If the color bleeds, then it’s best to wash the fabric before use. Use color-catcher laundry sheets to absorb the dyes.

If your fabric is second-hand, you may also want to wash it because you don’t know what the fabric has been in contact with.

It’s best not to wash pre-cut fabrics, like fat quarters and jelly rolls, before use. These smaller bits of fabric could unravel a lot if washed, so you may not have enough fabric to meet your pattern requirements.

You can machine wash and tumble dry your fabrics, or wash them by hand and line dry. It depends on how you’ll wash and dry the final quilt. And if you want to protect the vibrancy of your fabric colors.

To hand-wash your fabrics, soak each one separately in cold soapy water for a few hours. Hot or warm water could increase the risk of the colors fading. Then air dry the fabrics on a washing line.

Next, iron every fabric you use, whether you washed it or not. Your fabric must be flat and crease-free to create accurate cuts.

What supplies you need to cut fabric for quilting:

  • A stable desk or table
  • Cutting mat that’s atleast 21″ wide
  • Quilting ruler (6″ x 24”)
  • Rotary cutter and spare blades
  • Fabric scissors
  • Heat erasable pen (or another fabric marking tool)

First, use a table that’s flat and stable. A wonky or uneven table makes cutting harder.

A large cutting mat is very helpful if you’re cutting full yards of fabric. Ideally, you want the biggest size you’ve got room for, but 21” is as small as you want to go. Quilting fabric is normally 42” wide, so you’ll have enough room for it when it’s folded in half.

The 6″ x 24” ruler is the most common size used by quilters to cut fabric strips from yardage. You use it with a rotary cutter to slice fabric in straight lines.

Your rotary cutter generally comes with a blade on it, but it’s best to buy a spare pack of blades. You generally need to replace the blade after 3+ projects because they’ll become dull and stop cutting well.

Fabric scissors are useful for snipping threads. You can also use them to cut your fabric, but generally, rotary cutters are used for this purpose. Rotary cutters are better at creating long, accurate cuts. However, if you’re just starting, you may not want to invest in one yet. In this case, you’ll need to draw lines on the fabric to help you cut straight with scissors.

To draw these, a heat erasable pen is ideal. The mark disappears with the heat of an iron, but make sure you test this on a scrap of fabric from your project first.

Related: 32+ Quilting Supplies for Beginners & Beyond (Tested)

How to cut perfect squares using a rotary cutter:

1. Square up your fabric

What does “square up your fabric” mean? It’s common to buy fabric with uneven edges along the width. It’s important to cut these jagged edges off and make them straight. This allows you to accurately cut your shapes on the right grainline.

Fold your fabric in half (selvage-to-selvage)

Find the selvage edges of your fabric. They’ll be on opposite sides, along the length. Here’s how to identify the selvage edges:

  • They’re a bit more tightly woven to prevent fraying and unraveling.
  • They normally have a row of tiny holes running along them.
  • They sometimes have writing printed on them.

Fold the fabric in half so both selvage edges touch. Make sure the “right sides” of the fabric are facing up (towards you). The “right side” means the side of the fabric that looks better. If both sides look identical then it doesn’t matter.

Place your fabric on a cutting mat

Align the folded side of your fabric with the 1-inch vertical line on the cutting mat. Align the wonky edge with one of the horizontal lines at the top of your mat. This gives you more space to cut long strips of fabric later. (Note: vertical lines go up and down. Horizontal lines go from side to side).

Here I’ve aligned my fabric with the 1″ vertical line and the 17″ horizontal line (look at the top left corner of the photo).

White fabric folded on a grey cutting mat with a quilting ruler on top
Folded fabric placed on a cutting mat. Photo credit: Daisi Toegel.

Cut the wobbly raw edge off

(Note: “Raw edge” means the cut edge of the fabric which often frays).

White fabric with a quilting ruler on top
The ruler has been moved up and is aligned with the 16″ horizontal line on the cutting mat. Photo credit: Daisi Toegel.

Push your rotary cutter along the edge of the ruler to create the cut.

A rotary cutter squaring off fabric
The wobbly edge has been cut off using a rotary cutter. Photo credit: Daisi Toegel.

If you don’t have a rotary cutter, use a fabric marking tool to draw a straight line along the ruler. Then remove the ruler and carefully cut along the line using fabric scissors.

You have now made the width of your fabric straight.

2. Cut your fabric into strips

In quilting, it’s very common to first cut your fabric into strips, then squares, rectangles, or any other shape. This is because it’s easier to cut strips into smaller pieces than it is to cut yardage into smaller pieces.

To cut a fabric strip, decide how tall the strip should be. Let’s say 3″ for this example. Place the ruler on the fabric horizontally. Line up the 3″ mark with the edge of the fabric.

Then cut straight with the rotary cutter directly against the ruler. If you’re right-handed, go from the right to the left. And always cut away from your body to prevent accidents.

A quilting ruler and rotary cutter on top of white fabric
Getting ready to cut a strip of fabric. Photo credit: Daisi Toegel.

Tip: Your ruler may slide a bit while you’re cutting. To solve this problem, you can use attachments that give rulers more “grip” and stop them from moving about. For big rulers, try adding a ruler grip with double suction cups to the top. Or try True Grips non-slip adhesive rings on the bottom of your ruler. This option suits any ruler size.

3. Cut the selvage edges off the strips

The selvage edges are a bit stiff and normally have tiny holes in them. We don’t want this part of the fabric in our quilt, so let’s cut it off.

Align the ruler with the selvage edges at a right angle. Trim off the selvage edges.

Selvage edge being trimmed off
Getting ready to cut the “furry” selvage edge off. Photo credit: Daisi Toegel.

Note: you could have cut your selvage edges off when you squared your fabric. However, if you’re cutting long lengths of fabric that don’t fit on your cutting mat, it would be annoying cutting part of the selvage edge off, moving the fabric up, and then cutting the rest. So that’s why it’s being done at this stage.

4. Cut the strips into smaller squares

Decide how wide you want your squares to be (eg. 3″). Measure the required width using your ruler, then cut the strips into smaller squares using your ruler and rotary cutter.

Quilting ruler on top of a white fabric strip
Photo credit: Daisi Toegel

Alternatively, you can use the measurements on the mat to line up the fabric and cut the right width.

Quilting ruler on top of a white fabric strip
Photo credit: Daisi Toegel
white fabric strip cut into patchwork squares
A strip cut into multiple squares. Photo credit: Daisi Toegel.

How to cut a small number of squares (no strips):

What if you only need to cut a few squares and don’t want to waste a full strip of fabric? One option is to place a square quilting ruler on top of your fabric, and then cut around it. Be careful not to move the ruler whilst cutting.

hands cutting around a yellow quilt ruler with a rotary cutter
Cutting around a square ruler using a rotary cutter. Photo credit: Daisi Toegel.

Can I cut quilt squares with fabric scissors?

It’s possible to cut squares with fabric scissors, but not recommended. It takes longer and is less precise than rotary cutters. Even though you’ll be cutting on a line, scissors are considered a free-cutting method. 

If you do want to use scissors, make sure you draw lines first and cut along them carefully.

How to cut perfect quilt squares using fabric scissors:

Method 1: Cut 1 square at a time (recommended)

  1. Place a square ruler or template on top of your fabric.
  2. Use a fabric marker to draw around it.
  3. Remove the ruler or template.
  4. Cut along the lines you drew. 
a square drawn onto white fabric, and quilting supplies
A square drawn on a single layer of fabric. Photo credit: Daisi Toegel.

Method 2: cut multiple squares at a time

  1. Fold a bigger piece of fabric as many times as you can to fit the desired square size.
  2. Press the fabric layers flat with an iron.
  3. Place a square template or ruler on top of your fabric.
  4. Use a fabric marker to draw the square.
  5. Remove the template or ruler.
  6. Cut along the lines you drew. You’ll be cutting through multiple layers in one go, so be careful not to let the layers shift.

This is not my preferred way. The fabric layers could shift during the cutting process and create inaccurate squares.

a hand holding white folded fabric
Fabric folded multiple times. Photo credit: Daisi Toegel.
a hand cutting quilt squares using fabric scissors
Cutting through multiple layers. Photo credit: Daisi Toegel.

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This article was written by Daisi Toegel and edited by Sara Maker.