Use a size 16/100 or 18/110 needle for most jeans

A size 16/100 needle is the standard choice for sewing jeans and other medium-weight denim. If your denim is particularly thick — raw denim, multiple layers, or heavy canvas — move up to a size 18/110. These larger needles have thicker shafts and sharper points that push through dense fabric without bending or breaking, and they create a hole large enough that thread doesn't shred as it passes through.

The two numbers mean the same thing: 16 is the old metric size, 100 is the newer American size. Needle packages show both. Do not use a size 14/90 or smaller on jeans — the needle will flex under pressure, skip stitches, or snap. Do not use a size 20/120 unless you are sewing multiple layers of heavy canvas or leather; it will leave visible holes in single-layer denim.

The needle type also matters. Use a universal needle for regular denim, or a denim needle (also called a jeans needle) if your machine has trouble with skipped stitches. Denim needles have a reinforced shaft and a special scarf design that handles thick fabric more reliably. They cost a few cents more per needle and are worth it if you sew jeans regularly.

Key Takeaways

  • A size 16/100 universal or denim needle works for most jeans; use size 18/110 for raw denim or multiple layers.
  • Needle size is shown as two numbers (16/100, 18/110) — both refer to the same thickness, just different measurement systems.
  • A needle that is too small will bend, skip stitches, or break under the pressure of thick fabric.
  • Denim needles have a reinforced shaft and handle dense fabric better than universal needles, though universal needles work for casual jeans sewing.
  • Change your needle after every project or every 8 to 10 hours of sewing; a dull needle causes skipped stitches even in the right size.

Why needle size matters for denim

Denim is tightly woven and dense — much thicker than cotton quilting fabric or knit. A needle that is too small cannot push through the fibers cleanly. Instead, it flexes sideways as it enters the fabric, which causes the thread to miss the hook that catches it on the underside. This shows up as skipped stitches: a line of stitches on top but nothing underneath, or gaps in the seam.

A needle that is too small also heats up from friction and can snap mid-seam. If you hear a sharp pop or your needle suddenly stops moving, the needle has broken. A larger needle distributes the force over a wider shaft, so it stays straight and doesn't overheat.

The needle point also matters. Universal needles have a slightly rounded point designed for woven fabric. Denim needles have a sharper, more acute point that pierces dense weave more cleanly. If you are sewing jeans on a budget, a size 16/100 universal needle will work, but a denim needle of the same size will produce fewer skipped stitches and last longer.

Needle size for different denim weights

Not all denim is the same thickness. Lightweight chambray or shirting denim can be sewn with a size 14/90 needle, though a size 16/100 is safer and still appropriate. Standard five-pocket jeans, work pants, and most ready-to-wear denim are size 16/100 territory.

Raw denim (unwashed, stiff denim used for premium jeans) and heavy-duty workwear fabrics need a size 18/110. If you are hemming jeans and sewing through two or three layers of folded denim at the cuff, use size 18/110 for that seam even if the rest of the garment is size 16/100.

If you are sewing multiple layers — say, attaching a patch or reinforcing a seam — count the layers. Two layers of standard denim equal one layer of heavy denim; three layers call for size 18/110. When in doubt, test on a scrap first. Sew a short seam on a folded piece of your fabric and check for skipped stitches before committing to the full garment.

How to tell if your needle is the wrong size

Skipped stitches are the most common sign. If your top thread shows but the bobbin thread does not, or if there are gaps in the line of stitching, the needle is too small or too dull. Stop and change the needle before you sew further — a bad seam in jeans will fail under wear.

A needle that is too small may also cause the thread to shred or fray as it passes through the fabric. You will see fuzzy bits of thread around the needle or hear a grinding sound as the machine struggles. The needle may also bend without breaking, which causes stitches to form at an angle instead of straight down.

If the needle breaks, stop when ready and inspect the needle hole in the throat plate (the metal piece around the needle). Broken needle fragments can jam the bobbin area. Remove the needle, thread, and bobbin, then use a small brush or compressed air to clear any debris before inserting a new needle.

Changing and storing needles

Change your needle before starting a new project, or after every 8 to 10 hours of continuous sewing. A dull needle causes skipped stitches even if it is the correct size. Denim dulls needles faster than lighter fabric because of the friction, so if you sew jeans regularly, change needles more often.

Store needles in their original package or in a needle case. Do not leave them loose in a drawer where they can bend or rust. Keep a small notebook or label on your machine noting which needle size and type you are currently using — this saves time when troubleshooting and helps you remember what worked last time.

Buy needles in bulk if you sew regularly. A pack of 10 needles costs a few dollars and lasts through many projects. Buying individual needles at checkout is more expensive and often means you run out mid-project.

Universal needles versus denim needles

A universal needle has a slightly rounded point and a medium-depth scarf (the indentation on the back of the needle). It works on most woven fabrics, including denim, and is the most common needle type. If you own one sewing machine and sew a mix of projects, universal needles are your default.

A denim needle has a sharper point, a deeper scarf, and a reinforced shaft. The sharper point pierces dense weave cleanly; the deeper scarf gives the thread more room to sit before the hook catches it, reducing skipped stitches. The reinforced shaft resists bending under pressure. Denim needles cost slightly more but are worth the investment if you sew jeans, canvas, or heavy workwear regularly.

For casual jeans hemming or a single project, a size 16/100 universal needle is fine. For a wardrobe of handmade jeans or frequent denim repairs, buy a pack of denim needles. You will notice fewer skipped stitches and less needle breakage.

Frequently Asked Questions

Can I use a size 14 needle on jeans?

A size 14/90 needle is too small for most jeans and will cause skipped stitches or break under pressure. Use size 16/100 as your minimum. Size 14 works for lightweight chambray or denim shirting, but if you are unsure about your fabric weight, size 16/100 is the safer choice.

What is the difference between the two numbers on a needle package?

The first number (16) is the metric size; the second (100) is the American size. They refer to the same needle thickness — the package shows both systems so you can find the needle you need regardless of which labeling your machine manual uses. Buy whichever package is clearer to you.

Do I need a special needle for topstitching jeans?

Topstitching (the visible decorative stitching on seams and hems) uses the same needle size as the rest of the garment — size 16/100 for standard jeans. Some sewers use a topstitching thread, which is thicker, but the needle size stays the same. If you want extra-bold topstitching, you can use a size 18/110 needle, which creates a slightly larger hole and shows the thread more prominently.

What happens if I use a needle that is too large?

A needle that is too large leaves visible holes in the fabric and can damage the weave, especially in lighter denim. The seam will also look loose and may not hold under stress. Stick to size 16/100 for standard jeans and size 18/110 only for heavy raw denim or multiple layers.

How do I know if my needle is dull?

A dull needle causes skipped stitches, pulls threads, or creates a rough, uneven line of stitching. You cannot sharpen a sewing machine needle — they are too small and precise. When you notice skipped stitches or rough seams, change the needle. It is the cheapest and fastest fix.