Half Square Triangle Quilting Size Chart

We have created a Half Square Triangle Size Chart that will take the guesswork out of your cutting process. HSTs are a popular choice for quilters of all levels because they provide so many design possibilities. However, depending on the size of your finished quilt block, the size of your HSTs can vary.

This can be confusing for beginners, but fear not! Our Half Square Triangle Size Chart includes a range of common quilt block sizes and the corresponding HST size needed to create that block. We know that accuracy is key in quilting, so we have provided precise measurements for each HST size. With this chart, you can confidently cut your HSTs knowing that they will fit perfectly into your quilt block and result in a beautiful finished project.

Half Square Triangle Quilting Size Chart

Finished HST SizeFabric Square Size to CutYield per Pair of Squares

What Are Half-Square Triangles?

Half square triangles (HSTs) are a common quilting block that can be used to create a variety of quilt designs. They consist of two triangles made by cutting a square in half diagonally, resulting in a right triangle. The two triangles can then be sewn together to create a square with a diagonal seam.

The size of the finished HST block depends on the size of the starting square. To make it easy to determine the size of the starting square needed for a particular finished block size, quilters often use a half-square triangle size chart. This chart provides the dimensions of the starting square needed for a range of finished block sizes, taking into account the seam allowance that will be used to sew the triangles together.

By using a half-square triangle size chart, quilters can ensure that their blocks will be the correct size and that the points will line up accurately.

Definition and Uses

Half-square triangles are an essential component of quilting. They are versatile enough to be used in many patterns, making them a staple in the quilting world. Half-square triangles are made by cutting a square into two triangles.

These triangles are then sewn together to create half-square triangles. They can be used in a variety of ways, including as borders or in the body of the quilt itself. Many quilters use half-square triangles to create star patterns, pinwheels, and other geometric shapes.

The options are truly endless when it comes to using half-square triangles in quilt making. So, if you enjoy quilting, mastering the half-square triangle will certainly come in handy.

half square triangle size chart

Standard Half Square Triangle Sizes

If you’re a quilting enthusiast, then you must be quite familiar with Half Square Triangles (HSTs). These are the building blocks of many quilt designs, and as such, it’s essential to understand the standard half-square triangle sizes. HSTs come in a variety of sizes, and each size has its own uses.

The most common half-square triangle sizes are 2″, 5″, 3″, 5″, 4″,

5″, 5″, 5″, 6″, 5″, 7″,

5″, 8″, 5″, 9″, 5″, 10″,

5″, and 11″. These sizes create precise HST blocks, which can be used for many quilt designs, making them a must-have for any quilter’s toolbox. Plus, each of these sizes adds a unique touch to a quilt design, revealing the creativity and style of the quilter.

Therefore, it’s essential to have a half-square triangle size chart at hand, which will help you select the perfect size for your quilting project.

List of Common Sizes and Their Uses

Half-square triangles are a popular quilting element that can be found in countless designs and patterns. Knowing the common sizes that are used can help you create precise and beautiful projects. The standard half-square triangle sizes range from 1 inch to 7 inches, with half-inch increments in between.

The most commonly used half-square triangle size is 2 ½ inches. This size is great for beginners because it is easy to work with and can be used in various patterns. Larger half-square triangles, like 4 ½ inches and 6 ½ inches, are better for more complex designs that require bigger pieces.

On the other hand, smaller half-square triangles, like 1 ½ inches and 2 inches, are perfect for intricate and detailed designs. Remember, these sizes are just suggestions, and you can use any size that you prefer. The right size will ultimately depend on your project’s needs, so don’t be afraid to experiment and find what works best for your design.

How to Calculate Half-Square Triangle Sizes

If you’re new to quilting or just need a refresher, figuring out the size of your half-square triangles can seem daunting. Luckily, using a half-square triangle size chart can make the process much easier. This chart will give you the finished size of the half-square triangle based on the desired size of the block.

For example, if you want a 4-inch finished block, the chart will tell you to cut two 4 7/8 inch squares (or two squares that are 1 3/8 inches bigger than your desired finished size). Then, you will draw a line diagonally from one corner to the other on the back of one of the squares, sew 1/4 inch on each side of that line, and then cut along the line to create two half-square triangles. Using a half-square triangle size chart takes the guesswork out of the equation and helps ensure that your finished quilt blocks are the size you intended.

Step-by-Step Guide with Examples

Calculating half-square triangle sizes can be a daunting task for beginners and even experienced quilters. However, with a few simple steps, you can quickly and easily determine the size of your HST block. Firstly, decide on the size of the finished HST block that you want, and add 7/8 inch to this measurement.

This extra length will allow for seam allowance. Once you have your measurements, cut two squares from your chosen fabrics with this dimension. For example, if you want a 4-inch finished HST, cut two 4 7/8-inch squares.

Next, place the fabric squares right sides together and draw a diagonal line from one corner to the opposite corner. Sew ¼ inch away from the line on either side and then cut along the line. Press the seams open, and you now have two HSTs that are half an inch bigger than your desired size.

Trim the blocks to your desired size using a ruler and cutting mat. And voila! You have successfully and easily calculated your HST sizes.

Tips for Accurate Half-Square Triangle Sizing

If you’re a quilter, you know that Half Square Triangle (HST) blocks are a versatile building block for many quilt designs. However, achieving the right size can be tricky, and can make or break the finished product. To help with this, using a half-square triangle size chart can make a big difference.

The chart will provide a guide for creating squares that will ultimately become triangles. You’ll want to add an extra 7/8″ to your HST squares to ensure the proper size and seam allowances. You can also try trimming your blocks down to the exact size after piecing.

It’s important to remember that accuracy is key in quilting, so take your time to ensure that your HST blocks are the right size to make your finished quilt look its best. With practice and attention to detail, you can achieve perfectly sized half-square triangles every time.

Cutting, Sewing, and Pressing Techniques

Half-Square Triangle If you’re looking for tips and techniques for creating precise and accurate half-square triangles, then you’ve come to the right place! There are a few key steps that you can take to ensure that your triangles are sized just right, every time. First off, it’s important to start with accurate cutting. Make sure that you’re cutting your fabric pieces to the exact size that you need, and that you’re using a sharp rotary cutter or scissors to ensure clean edges.

When it comes to sewing, a 1/4-inch seam allowance is standard for most quilting projects. However, some quilters find that a slightly smaller or larger seam allowance works better for them. The key is to be consistent with the seam allowance that you choose and to sew with precision.

Once you’ve sewn your half-square triangles, pressing is also important. Use a hot iron and press firmly, but be careful not to distort the shape of the triangle. Pressing your seams to one side or opening also plays a factor in the final measurement of your half-square triangles.

Finally, it’s important to square up your half-square triangles to ensure accuracy. Use a ruler to trim your triangles to the exact size that you need, and make sure that you’re trimming all four sides to maintain a perfect square. With these tips and techniques, you can create beautiful and precise half-square triangles for all of your quilting projects.


In conclusion, the half-square triangle size chart is like a treasure map for quilters, guiding them to the perfect dimensions for creating this popular building block. It’s a blueprint for creativity, offering infinite possibilities for creating breathtaking designs. So whether you’re a seasoned quilter or a novice, let this chart be your compass and set sail on a quilting adventure unlike any other!”

Summary of Important Points

Half Square Triangle Sizing If you’re a quilter, you’re probably already familiar with the half-square triangle, or HST. It’s a simple, versatile block that can be used in countless patterns and designs. One of the most important aspects of creating a good HST is getting the sizing just right.

Here are a few tips to ensure accuracy when sizing your HSTs. Firstly, start with perfectly square pieces of fabric. This is essential for accurate HST sizing.

Secondly, use a ruler with a 45-degree angle on it for marking your fabric. This will ensure that your HSTs have straight, even edges. Thirdly, when sewing your HSTs together, be sure to use a consistent ¼ inch seam allowance.

This will help ensure that your blocks come out the same size. Fourthly, when pressing your HSTs, be sure to press carefully, taking care not to distort the fabric. Finally, square up your HSTs after sewing to ensure that they are the correct size.

By following these tips, you’ll be able to create accurate, perfectly sized HSTs every time. Remember to take your time, be careful, and, most importantly, have fun!


What are the common sizes of half-square triangles in a quilt?
The most common sizes of half-square triangles are 1.5″, 2″, 2.5″, 3″, 3.5″, and 4″.

How do I choose the right size of the half-square triangle for my quilt project?
The size of the half-square triangle you choose will depend on the design of your quilt. Consider the finished size of your quilt blocks and the size of any other pieces in the design. A general rule of thumb is to choose a size that is half an inch larger than the finished size of your block.

Can I make my own half-square triangle size chart?
Yes, you can create a custom half-square triangle size chart based on your quilt project. To do this, determine the finished size of your quilt blocks and the desired size of your half-square triangles. Then, use a quilting calculator or a quilting ruler to determine the size of the starting squares you will need.

What is the difference between a half-square triangle and a quarter-square triangle?
A half-square triangle is created by sewing two right triangles together along the hypotenuse (longest side) to form a square. A quarter-square triangle is created by cutting a square diagonally twice to form four triangles and then sewing two of those triangles together along the short sides. Quarter-square triangles have a more complex, diagonal pattern than half-square triangles.

Leave a Comment