Sewing Thread Size: Tex, Ticket Number and Needle Chart

Pick up three cones of thread from a factory shelf and you will see three different sets of numbers: Tex 27, Tkt 120, 40/2, Nm 37, maybe 150 denier on the side. Every number tries to say the same thing, which is the sewing thread size, but each follows a different system. That confusion costs real money. The wrong thread size gives puckered seams, broken threads, skipped stitches and slow lines.

This guide explains sewing thread size in plain words. You will learn what the main systems mean (tex, ticket number, denier, English count and metric count), how to convert between them, how thread thickness relates to needle size, which sizes suit which fabrics and a worked example that shows how thread size changes cone length and cost. If you work with thread consumption in a factory, our guide to the bill of materials in garments shows where thread fits in the order plan.

Why thread size matters

Thread has three jobs. It must hold the seam together, it must pass through the machine without breaking and it must look right on the garment. Thread size affects all three.

• A thread that is too thin may break under stress, and the seam may split.
• A thread that is too thick may pucker the fabric, wear out the needle eye and slow the machine.
• The wrong size for the needle causes skipped stitches, fraying and thread breaks.
• Sizes must match across a line so that stitch quality is consistent.

The main sizing systems

Thread sizing systems fall into two groups. In direct systems, a higher number means a thicker thread. In indirect systems, a higher number means a thinner thread. Mixing them up is a common mistake.

1. Tex (direct system)

Tex is the weight in grams of 1,000 metres of thread. A thread of Tex 27 weighs 27 g per 1,000 m. A higher tex means a thicker thread. Tex is the international standard and is used on most industrial thread labels.

Thread tex is usually the total tex of the finished plied thread, not the tex of each ply.

2. Denier (direct system)

Denier is the weight in grams of 9,000 metres. It is used for filament threads such as nylon and polyester.

Tex = denier ÷ 9

So 243 denier is 27 tex.

3. English cotton count, Ne (indirect system)

Ne is the number of 840-yard hanks in one pound. A higher Ne means a finer thread. Cotton thread and spun polyester thread are sometimes labelled with Ne, along with the number of plies, for example 40/2.

Tex = 590.5 ÷ Ne (for a single yarn)

4. Metric count, Nm (indirect system)

Nm is the number of kilometres of thread in 1 kilogram.

Tex = 1,000 ÷ Nm

5. Ticket number (Tkt)

The ticket number is a trade label used on many industrial sewing threads. It is an indirect number, so a higher ticket is a finer thread. As a rough rule:

Ticket number is about 3,000 ÷ tex

So Tex 27 is close to Tkt 120 (3,000 ÷ 27 = 111, and makers label it Tkt 120), and Tex 40 is about Tkt 75. Makers round and assign tickets differently by thread type, so use this rule only as a guide and check the maker’s chart.

What ply notation means

Sewing thread is made by twisting several thin yarns together. The numbers on the label often show the single yarn count and the number of plies.

• 40/2 means two plies of count 40.
• 50/3 means three plies of count 50.
• 120/3 may mean three plies, with the number related to ticket sizes in some brands.

The finished thread is thicker than one ply, so you must take the ply number into account.

Conversion table

Tex	Denier	Nm	Ne (single equivalent)	Approx. ticket	Typical use
18	162	56	32.8	170	Fine sewing, light fabrics
21	189	48	28.1	150	Shirts, blouses
27	243	37	21.9	120	General garment sewing
35	315	29	16.9	90	Trousers, work wear
40	360	25	14.8	75	Denim seams, heavy cotton
50	450	20	11.8	60	Jeans, upholstery
70	630	14	8.4	40	Topstitch on denim, canvas
105	945	9.5	5.6	30	Heavy leather, bags

The columns are calculated from the tex. The ticket column is approximate. These numbers are general guides, and every maker has its own chart. Always check the label on your brand of thread.

Matching thread to needle

Thread should pass freely through the needle eye and the groove along the needle blade. If it is too thick, it shreds. If too thin, it may cause loose stitches. The needle size is the blade diameter in hundredths of a millimetre, so a size 90 (Nm 90) needle has a blade of about 0.9 mm.

Thread tex	Typical needle size (Nm)	Fabric examples
18 to 21	60 to 70	Chiffon, lawn, fine lingerie
24 to 27	70 to 80	Poplin, shirting, jersey
30 to 35	80 to 90	Twill, trousers, light denim
40 to 50	90 to 100	Denim, canvas, work wear
60 to 70	100 to 110	Topstitch, heavy denim
90 and above	110 to 120	Upholstery, bags, leather

These pairings are common starting points, and exact matches differ by needle type, thread construction and fabric. For more on choosing a needle, see our guide to sewing needle parts, size and point selection.

Matching thread to fabric and seam

Think about four things.

1. Fabric weight. Light fabrics need fine thread. Heavy fabrics need thicker thread.
2. Seam strength. A stressed seam, such as a crotch seam or a bag strap, needs a stronger and thicker thread than a decorative seam.
3. Stitch type. Lockstitch uses one size for the needle thread and bobbin. Overlock uses finer thread in the looper than the needle thread in some cases. Topstitching uses thicker thread for a visible line.
4. Fibre. Polyester gives strength and low shrinkage. Cotton gives a soft look but weaker seams. Nylon suits stretch and heavy duty. Core-spun thread has a polyester core wrapped in cotton or polyester.

A simple rule: the thread should be a bit weaker than the fabric, so that if the seam is overstressed, the thread breaks before the fabric tears. Fine fabrics need thread of lower strength.

A worked example: cone length, weight and cost

Thread is sold on cones, usually by length. Let us see how thread size changes the numbers.

Given

• Cone length: 5,000 m
• Thread A: Tex 27
• Thread B: Tex 40
• Thread C: 50/3 cotton-type thread (single count Ne 50, three plies)
• Price: A is 2.50 per cone, B is 3.20 per cone

Part 1: weight of thread on a cone

Weight in grams = length in metres × tex ÷ 1,000

• Thread A: 5,000 × 27 ÷ 1,000 = 135 g
• Thread B: 5,000 × 40 ÷ 1,000 = 200 g

Part 2: price per kilogram and per metre

• Thread A: 2.50 per 0.135 kg = 2.50 ÷ 0.135 = 18.52 per kg. Per metre: 2.50 ÷ 5,000 = 0.0005.
• Thread B: 3.20 per 0.200 kg = 3.20 ÷ 0.200 = 16.00 per kg. Per metre: 3.20 ÷ 5,000 = 0.00064.

The thicker thread is cheaper per kilogram, but it costs more per metre. For sewing, cost per metre matters, because a seam needs a set length. B costs 0.00064 ÷ 0.0005 = 1.28 times more per metre than A.

Part 3: total tex of a plied thread

Take Thread C, 50/3.

Step 1: tex of one ply.

Tex = 590.5 ÷ Ne = 590.5 ÷ 50 = 11.81 tex

Step 2: total tex for 3 plies.

Total = 11.81 × 3 = 35.4 tex

So a 50/3 thread is about Tex 35, which is near the Tex 35 line of the table. This is the kind of size used for trousers or light denim. In practice, twist makes the thread a little shorter, and so the true tex is slightly higher.

Part 4: thread for a large order

Suppose a shirt uses about 130 m of thread, including allowances. For an order of 20,000 shirts of Tex 27:

• Total length = 130 × 20,000 = 2,600,000 m
• Cones = 2,600,000 ÷ 5,000 = 520 cones
• Weight = 2,600,000 × 27 ÷ 1,000 = 70,200 g = 70.2 kg
• Cost at 2.50 per cone = 520 × 2.50 = 1,300

If the factory switched to Tex 40 for the same shirt without need, the thread weight would rise to 2,600,000 × 40 ÷ 1,000 = 104,000 g = 104 kg, and the cost to 520 × 3.20 = 1,664. That is an extra 364 for no gain. Using the thinnest thread that meets the strength and look targets saves money.

Thread size and seam performance

Thread size affects seam strength, but the relationship is not simple.

• Thicker thread has higher breaking strength, but it also needs more space in the stitch hole.
• Very thick thread in fine fabric causes puckering and distorts the fabric.
• Stitches per inch (SPI) and thread tension also matter. A higher SPI uses more thread and can weaken the fabric by perforating it.

For this reason, buyers often define a seam strength requirement or a thread tex in the specification. Our guide to types of seams in garments shows how seam types change load and thread use.

Thread type quick guide

Thread	Description	Typical size	Best for
Spun polyester	Staple fibre, twisted, cotton-like look	Tex 21 to 40	General garment sewing
Core-spun	Polyester filament core, polyester or cotton wrap	Tex 27 to 40	High-speed sewing, strong seams
Continuous filament polyester	Smooth, strong, shiny	Tex 18 to 70	Heavy duty, bags, upholstery
Cotton	Soft, low strength, shrinks	Ne 30/2 to 50/3	Natural look, light use
Nylon	Strong, stretchy	Tex 18 to 70	Stretch seams, leather, outdoor wear
Textured polyester	Bulky, stretchy	Often 150 denier and up	Overlock loopers, swimwear
Embroidery thread	Rayon or polyester, shiny	120/2 and others	Decoration. See our guide to embroidery thread types

How to find the size of an unmarked thread

If a thread has no label, you can estimate its size.

1. Cut a known length. Use 1 metre, measured without stretching.
2. Weigh it on a precise scale. A jeweller’s scale that reads 0.001 g or finer is needed.
3. Calculate tex. Tex = weight in grams × 1,000 ÷ length in metres.

Example: 5 metres of thread weigh 0.135 g. Tex = 0.135 × 1,000 ÷ 5 = 27 tex.

If you do not have a good scale, weigh a longer length, such as 100 m, which is easier to measure. Another method is to compare with a known thread of the same colour by eye and by feel, but it is less reliable.

Common problems linked to thread size

Problem	Possible size cause	Fix
Thread breaks often	Thread too thick for needle eye, or too thin and weak	Match thread and needle, check tension
Skipped stitches	Needle too small for thread	Use a larger needle
Puckered seams	Thread too thick for the fabric	Use a finer thread
Seam splits	Thread too weak	Use a stronger or thicker thread
Visible stitch holes	Needle too large	Use a finer needle and thread
Uneven stitches	Different thread sizes in needle and bobbin	Use matching sizes unless the design says otherwise

Our guide on sewing defects and root causes goes deeper into causes and solutions.

Tips for choosing thread size

• Start with Tex 27 for general woven and knit sewing, then adjust.
• Use Tex 40 to 70 for jeans and heavy work.
• Check your buyer’s specification for thread type, tex and colour.
• Use the same brand for needle and bobbin where possible.
• Test seam strength and appearance on the actual fabric.
• Keep a conversion chart at the line for quick checks.
• Record the thread size on the operation breakdown and the BOM.

Final thoughts

Sewing thread size looks like a puzzle of numbers, but it comes down to one idea: how much a given length of thread weighs. Tex states it directly, denier does so for a different length, and ticket number, Ne and Nm tell the same story in reverse. Once you know the conversions, you can compare any two threads, match thread to needle and calculate how much a cone holds.

The best thread size is the thinnest one that gives the strength and look the seam needs. Use the charts here as a starting point, test on real fabric and keep a record of what works.

Frequently asked questions