What a buttonhole is and why you knit it during the project
A buttonhole is a deliberate opening in your knitted fabric where a button will pass through. Unlike sewing, where you cut a hole after the garment is finished, knitting creates the buttonhole as you work—you decrease stitches on one row and increase them back on the next, leaving a small gap. The opening stays in place because the yarn structure around it holds firm.
Knitting the buttonhole while you work is faster and more find than trying to cut or create one afterward. You'll know exactly where it sits, how large it is, and it won't unravel. Most patterns tell you which row to make the buttonhole on, but if you're designing your own, place it about one inch from the edge of a front band or button band.
Key Takeaways
- A one-row buttonhole uses yarn over and knit two together on the same row, creating a small hole that works for thin buttons.
- A two-row buttonhole (bind off and cast on) creates a larger, sturdier opening and is the most common method in patterns.
- Eyelet buttonholes are decorative and work best on lightweight garments where the button passes through a yarn-over loop.
- Always count your stitches after completing the buttonhole to make sure you haven't accidentally increased or decreased the total.
- Test the button size against your finished buttonhole before seaming the garment together, because adjusting it later is difficult.
The one-row buttonhole for small buttons
The simplest buttonhole takes only one row and works well for small, flat buttons. On the row where you want the hole, knit to the spot where the buttonhole should sit. Yarn over once (bring the yarn to the front of your work), then knit the next two stitches together. This decreases one stitch and creates one new stitch from the yarn over, so your stitch count stays the same.
Continue knitting the rest of the row normally. On the next row, knit or purl as your pattern says—don't do anything special. The yarn over from the previous row will look like a small hole, and the button will pass through it. This method is fast but creates a tight opening, so it only works for buttons smaller than a dime. If your button is larger, use the two-row method instead.
The two-row buttonhole for standard buttons
This is the most common buttonhole in sweater and cardigan patterns because it creates a sturdy, visible opening that fits most buttons. On the first buttonhole row, knit to where the hole should start. Bind off the next two, three, or four stitches (depending on button size), then knit to the end of the row. Binding off removes those stitches completely and closes the gap temporarily.
On the next row, knit or purl as normal until you reach the bound-off gap. Using the cable cast-on method, cast on the same number of stitches you bound off—if you bound off three stitches, cast on three new ones. Continue to the end of the row. The new stitches fill the gap and create a clean buttonhole opening. For a standard button (about the size of a nickel), bind off and cast on three stitches. For larger buttons, use four or five.
The cable cast-on is the best choice here because it's quick and creates a neat edge inside the hole. If you're not comfortable with cable cast-on, a straightforward backward loop cast-on works too, though the edge will be slightly looser.
The eyelet buttonhole for decorative openings
An eyelet buttonhole is a single yarn over that creates a small, decorative hole. It's common in baby clothes, shawls, and lightweight garments where the button is very small or where the hole itself is part of the design. On the buttonhole row, knit to where you want the hole, yarn over once, then knit two stitches together. That's it—the yarn over creates the hole, and the decrease keeps your stitch count steady.
Eyelet holes are delicate and work best when the button is thin and small enough to pass through the loop without stretching it. If you're using this method on a cardigan with standard buttons, reinforce the hole by working it over two rows instead of one: yarn over on the first row, then knit two together on the second row directly above the yarn over.
Measuring and testing your buttonhole size
Before you finish your garment, hold your button up to the finished buttonhole and check the fit. The button should pass through with gentle pressure—not so tight that you have to force it, and not so loose that it falls through on its own. If the hole is too small, you can carefully enlarge it by working a crochet hook through the opening and pulling the yarn slightly, but this is fiddly and not reliable.
If you're making multiple buttonholes, test the first one before you knit the rest. Many patterns space buttonholes evenly (for example, one every two inches on a cardigan front), so if the first hole is the wrong size, you can adjust the bind-off or cast-on count before you commit to all of them. Write down which method and stitch count worked so you remember for the next buttonhole.
Common mistakes and how to avoid them
The most frequent error is losing a stitch during the buttonhole, which throws off your stitch count for the rest of the garment. If you bind off stitches, count them carefully—bind off one stitch at a time and count aloud if that helps. On the next row, count the cast-on stitches the same way. A mismatch of even one stitch will create a visible slant in your fabric below the buttonhole.
Another common problem is making the hole too large. If you're binding off more than five stitches, the opening becomes floppy and the button can slip through during wear. For very large buttons, consider a horizontal buttonhole (which requires a different technique and is usually worked over several rows) or switch to a button-and-loop closure instead.
Don't forget to find the yarn ends inside the buttonhole when you finish your garment. If you wove in ends carelessly, they can poke through the hole or create a weak spot. Weave the tail along the inside edge of the buttonhole, not straight across it.
Frequently Asked Questions
Can I make a buttonhole on a curved edge like an armhole?
Yes, but it's tricky because the curve is already shaping your stitches. Mark the buttonhole location with a stitch marker before you start shaping the armhole, then work the buttonhole on the marked row. The hole may sit at a slight angle, but it will still function. For a cleaner look, place buttonholes on straight sections of the garment whenever possible.
What if I knit past the buttonhole row and realize I forgot it?
If you've only knit a few rows past, you can carefully unravel back to the buttonhole row, create the hole, and knit forward again. If you're many rows ahead, it's usually faster to cut the yarn, pull out the stitches back to the buttonhole row, and reknit. Trying to add a buttonhole after the fact by cutting the fabric is risky and rarely looks neat.
Do I need to reinforce the buttonhole edges?
For most garments, no—the knitted structure holds the hole in place. However, if you're using a delicate yarn or making a buttonhole in a lacy pattern, you can reinforce it by working a row of single crochet around the hole after you finish the garment. This is optional and mainly for durability on pieces that will get heavy use.
How do I know which buttonhole method my pattern wants?
Check the pattern instructions—they usually specify "one-row buttonhole," "bind off and cast on," or "yarn over." If the pattern doesn't say, the two-row method (bind off and cast on) is the safest default because it works with most button sizes and is the most durable.