Sewing Thread Size Chart: Understanding Thread Sizes (2022)

Threads are special types of yarn that are specially engineered to pass through your sewing machine without any resistance.

Threads can help you form stitches without them breaking or becoming distorted.

Apart from its fineness, color and luster, you need to pay special attention to the size of the thread.

Even a small error in selecting the right thread can cause a loss on investment with your materials!

Using Size Charts

Using a sewing thread size chart could help you a lot, especially if you are a beginner.

It can be difficult to figure out the answer to questions like, “what is the right thread size?” or “what thread should I use for my machine?”

Instead of pondering aimlessly for too long, you can just refer to a chart that will tell you exactly what you need to buy.

What is thread size?

Red Sewing Thread

Thread size tells you how thick a thread is and how much it weighs.

Thread size is different from the actual thread weight in grams, and there is a system to work it out.

A spool of thread could be numbered 60, but another may have 60wt written on top. Note that these two threads are not the same.

The numbers that reflect thread sizes are decided by weight and length in meters of thread, and will establish if your thread is measured in denier, tex or an alternative measurement.

How is sewing thread size measured?

Since all threads have a circular cross section, the accepted way to measure a sewing thread is to use the linear density.

Thread size measuring systems are used to express the relationship between the unit of length and weight of the thread, which also reflect the thread’s diameter.

Threads are usually made up of several single strands that are twisted together and numbered by:

  • The thickness of the single strand.
  • The number of strands. The thickness of the strand is measured by the weight related to the length of a particular unit.

Direct count systems

Close Up of Blue Thread
Close Up of Blue Thread

Direct count systems depict thread size by determining the weight of a fixed length section. The following are the common direct count systems that reflect thread sizes:

Tex (T)

Tex is the most consistent measuring method, and most sewing thread sizes will be measured with it. It uses a fixed length to measure the weight of a thread.

Thread tex is the weight in grams of 1,000 meters of thread, so for example 1,000 meters of thread has a wt of 1gm. Important: the higher the tex, the thicker the thread.

For example:

If 1000 meters weighs 25grams, its thread will be 25 TEX. Thread tex-15 and thread tex-20 are fine threads often used in blind stitching and heirloom projects.

T-40 is the most common thread size and is most commonly used for general sewing work. T-70+ are coarse threads used for top stitching and buttonholes.

Denier Count (Td or d)

Denier is also used to measure thread at a fixed length. It is the fixed wt in grams of 9,000 meters of thread. This description is used in nylon fabrics, which are often classified by the denier of the threads from which they are woven.

For example:

Denier thread of 9,000 meters of thread; weighs 150grams, it’s 150-denier thread.

Most rayon and polyester embroidery threads are 120 / 2.

This represents a 2 strand mix weighing 120-denier each, making a total of 240 denier.

Denier Size

Generally, larger denier sizes mean heavier threads. Thread sizes between 135D and 180D are fine threads, while between 630D and 900D are coarse threads. The most common thread size is 350D, which is used for general industrial sewing.

Indirect count systems

Sewing Thread On a Machine
Sewing Thread On a Machine

Indirect count systems reflect thread diameter by referencing from another measurement.

Metric count

The metric count reflects the thread size by comparing length to the weight. It refers to the weight in grams of 1000 meters of thread. Threads with a higher metric count are generally thinner in comparison to threads with a lower metric count.

Count cotton (NeC, NeB or Ne)

This is an indirect system that is used to depict the thread size. The thread size is measured based upon the individual size or strand.

Threads with a count between 120 – 160 are considered fine, but threads with a cotton count between 22 – 34 are considered coarse.

Hong Kong tkt

This is the same as a cotton count, the one difference being that the number is written without a slash, e.g. a 50/2 count means a 502 Hong Kong Count ticket.

Gunz count

This was developed in Japan to determine thread sizes and is generally written ‘#60’. The smaller number represents fine threads while larger numbers represent coarse threads.

Commercial sizes

Commercial sizes of thread are used when sewing heavier fabrics like canvas upholstery. Industrial or commercial sizes are set sizes of 30, 46, 69, 92, 128, 207, 277, 346, 415 and 554.

They are the threads denier that’s divided by 10.

Thread size chart

ThicknessWeightGunze CountUsed For
Light60#60/3Bobbin, applique
Thin50#50/3Bobbin, applique
Regular40#40/3All purpose, quilting
Upholstery, Heavy30#30/3Decor
Heavy Duty20#20/3Decor
Thread Weight Table

There are a number of things to look for in a thread size system.

Many industrial and home sewing machines will read measurements differently, but you can easily find a chart or system that will take that into account. Check out the one below!

This chart is fairly simple to follow for a beginner.

You can simply follow the weight in grams of the sewing thread sizes along with the gunze count and match it up to your project.

Count system

There are many other measurement units for thread sizes in addition to weight, tex and den. There is something on the thread called the ‘ticket number’, which is an internal thread reference for the manufacturer.

Sure, there are complicated formulas that can derive the denier tex or weight from the ticket number. But, they are mostly used for commercial sizes and you probably won’t have to worry about them too much in practice.

Industrial Sewing

The following measurements are exclusively used in industrial sewing: metric ticket number (Nm), Cotton Count (NeC, NeB or Ne), Hong Kong Ticket (sometimes named far east) , decitex and others.

Things to consider

The fabric you’re using will ultimately decide the type of thread you will want to use. It should match the size, weight and properties of the materials you will be working on.

TIP

Some sewists recommend that you match the thread content to the fabric’s content.

Brand

Like in all industries, there are some big brands out there selling sewing threads. I usually buy sewing threads online, as it’s more convenient and I have my favorites.

I like brands such as Milijia or Leonis but you can also find other cheap sewing threads. Try not to buy thread only from the discount bin (I know it’s tempting), as it could be difficult to sew with.

Type of thread

When choosing the right thread size for your project, you might come across these terms: thread play, corespun thread, corded thread and threaded twist.

It is up to you to calculate the thread size, based upon the denier or tex system.

NOTE

It’s important to note that not all types are suitable to be used for heavy projects.

Converting sewing thread sizes

There exist some complicated formulas to use when trying to work out the different thread size conversions.

For most of us home sewists, it’s pretty easy to work out the thread size based on the numbers printed on the thread spool and the written count.

If you want a very detailed conversion guide for denier size sewing, I’ve found this one online.

What are standard or commonly used thread sizes?

It of course depends on the fabrics and project you will be creating. Thread for leather will be very different to a light denier sewing projects.

The most common thread is nylon or polyester thread / cotton which is a multipurpose and suitable for all types of fabrics including stretch. The most common sizes are denier 30 wt, 40 wt, tex 70.

Choosing the right thread sizes

Selecting the right thread size is important, as it will influence the stitch quality. The thread size measures the thread’s thickness.

If another weight is given for thread (like ounces), it’s referring to the amount of thread on the spool.

Here’s an informative video comparing different thread sizes

Thread Talks: Differences Between Thread Weights: Where to use them & how they look

If you use the wrong thread size, you may encounter a jam on your sewing machine, or in other cases the thread might break.

There are some things to consider when selecting the right size thread denier for your project:

Things To Consider

Type of sewing

When using a sewing machine, V-69 are the heaviest commercial sizes of thread, and are recommended for home sewing machines.

If you will be working by hand, you have the freedom to select a thread you feel is most suited to the project.

Type of materials

Heavier threads make your denier stitching more visible.

Some sewists prefer to use 100% cotton or nylon thread to match 100% cotton upholstery. If you use a thread denier that’s too heavy duty for the materials you are using, it may end up looking a little like a caterpillar!

Thread tension

The tension on your machine will need adjusting when you switch thread weights. When thicker thread needs to be used for heavy projects, you also need to decrease the tension on your machine.

Conversely, when you use a thinner thread for lightweight fabrics, the tension will need to increase to make the machine run smoothly.

Needle size

Because the thread is used in combination with a needle, you will need to consider the thread size together with the recommended sewing machine needle type and size.

As a rule of thumb, you can try to use a needle where the eye is 40% larger than the thickness of the thread.

Thread package

Definitely pay attention to the thread package, as it’s labeled with the measurement numbering systems.

On the top and the bottom of the spool will sit stickers that give you the information about the wt or tex of the thread, and what the material the thread is made from e.g. 60% polyester, 40% cotton.

NOTE

Don’t forget that with weight, the smaller the number the larger the thread, but with tex it’s the other way around.

Warning

Not all sewing thread size charts are accurate though.

You should take the time to find the sewing thread size chart that is accurate for you and your machine.

A thread size guide is an essential tool for any entry level sewist!

Conclusion

While different threads may appear identical to the naked eye, they could not be more different!

I hope this has given you a little insight into the world of thread sizes and you understand the differences between the common terminologies now! And if you need sewing patterns, here’s my collection. Happy crafting.

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Kris Daub
Kris Daub
[email protected] byCurated I'm a maker at heart! I love to create and tech others to create. I particularly sewing and hand crafts like ebroidery. I also love larger home decorating projects. ✂️ 🧵