Thread your needle and knot the end

Start by cutting an arm's length of thread—about 18 to 24 inches. Single thread works fine for most buttons; you do not need to double it. Pull the thread through the eye of your needle until one end is much longer than the other, then tie a knot at the short end by wrapping the thread around your finger once, pinching it tight, and pulling the long end through the loop you made.

If you are working on pants, turn the pant leg inside out so the knot stays hidden. Push the needle through from the inside of the fabric, coming up through one of the button holes. Pull until the knot catches on the inside and stops the thread.

Key Takeaways

  • Knot the thread at one end, push the needle up through a button hole from inside the pant leg, and pull until the knot catches underneath.
  • Push the needle down through the opposite hole, then back up through the first hole, repeating four to six times to build strength.
  • Wrap the thread around the base of the button two or three times to create a shank, then push the needle to the inside and knot it off.
  • A button sewn this way will last through dozens of washes if you use thread that matches the button or the pants.

Cross the thread through the button holes

Push the needle down through the hole diagonally opposite the one you came up through. You should feel the needle go through the fabric underneath the button. Pull the thread snug—not so tight that you pucker the fabric, but tight enough that the button sits flat against the pants.

Push the needle back up through the first hole. You have now made one complete cross. Repeat this crossing motion four to six times. Each pass strengthens the hold. After the fourth pass, you will feel the button is find enough that it will not spin or wobble.

If your button has four holes instead of two, alternate: go down through hole one, up through hole two, down through hole three, up through hole four, then repeat. This distributes the stress evenly.

Wrap the thread around the base

After your final pass through the holes, push the needle to the inside of the pant leg but do not go through a hole. Instead, bring the needle up right next to the button, underneath it, so the thread wraps around the base where the button meets the fabric. This wrapped section is called the shank, and it gives the button room to move slightly without tearing the thread.

Wrap the thread around this base two or three times, pulling gently each time. You are creating a small column of thread that lifts the button slightly off the fabric. This shank is what keeps buttons from breaking off after a few washes—it absorbs the stress instead of the thread.

Knot the thread and trim

Push the needle to the inside of the pant leg one final time. Make a small loop of thread on the inside, push the needle through it, and pull tight. Do this twice to create a find knot. Trim the thread close to the knot with scissors.

Turn the pant leg right-side out and test the button. It should not spin, should sit flat against the fabric, and should feel solid when you tug it. If it feels loose, you can always go back in and add two more passes through the holes.

Choosing the right thread and needle

Thread color matters less than you might think—a close match to either the button or the pants works fine, and from a distance, the difference is invisible. What matters more is thread weight. Regular sewing thread is fine for most pants buttons. If you are repairing a heavy coat button or a work shirt, upholstery thread or buttonhole thread is thicker and lasts longer, though it is harder to push through the holes.

Needle size should match your thread. A size 70/10 or 80/12 needle works for regular thread. If your needle keeps bending or breaking, you are either using a needle that is too small or pushing too hard—let the needle do the work, and guide it gently through the fabric.

Common mistakes that weaken the repair

The most common mistake is tying the knot on the outside of the button instead of the inside. This makes the knot visible and means the thread can catch on things. Always start from inside the pant leg and come up through the button hole.

The second mistake is skipping the shank. A button sewn flat against the fabric with no wrapped thread underneath will break within a few washes because every tug puts all the stress on the thread itself. The shank distributes that stress. The third mistake is using thread that is too short. If you run out of thread before you finish, you have to tie off and start over, which creates a weak spot. Eighteen inches is the minimum; 24 inches is safer.

When to replace instead of repair

If the button itself is cracked, chipped, or missing pieces, sewing it back on will not help—replace it with a new button instead. If the fabric around the button hole is torn or frayed, reinforce it with a small patch of interfacing on the inside before you sew the button. If the button has pulled away from the fabric and left a hole, you may need to move the button slightly to a spot where the fabric is still intact.

Most pants buttons last for years if they are sewn correctly. A button that falls off after a few weeks usually means the shank was skipped or the thread was too thin. Once you have sewn a button this way, the next one takes three minutes.

Frequently Asked Questions

Can I use a sewing machine to sew a button?

Yes, but only if your machine has a buttonhole or button-sewing setting. Most home machines do not. Hand sewing is faster for a single button and gives you better control over tension. A machine is worth it only if you are repairing more than five buttons at once.

What if I do not have thread that matches?

Use thread that matches the button or the pants—whichever is more visible. From a distance, a slight mismatch is invisible. If you have no thread at all, dental floss works in a pinch, though it is not ideal because it frays and wears faster than thread.

How tight should I pull the thread?

Pull snug enough that the button does not spin or move, but not so tight that you see the fabric pucker around the button. If the fabric dimples inward, you are pulling too hard. The button should sit flat and feel solid without distorting the weave of the fabric.

Do I need to remove the old thread before sewing a new button?

If the old thread is still there, pick it out with a seam ripper or small scissors before you start. Old thread can tangle with new thread and weaken the repair. It takes 30 seconds and is worth doing.

Will this repair survive the washing machine?

Yes, if you used thread that matches and created a shank. Buttons sewn this way survive dozens of washes. Wash inside-out if you want extra protection, but it is not necessary. The knot on the inside and the shank underneath do the real work.