What Knit Front and Back Does
Knit front and back (often written as KFB) is a way to increase one stitch by working twice into the same loop. You knit into the front of a stitch the normal way, leave it on the needle, then knit into the back of that same stitch before dropping it off. You end with two stitches where you started with one.
This increase is common in shaping — sleeves, hats, and increases across a row. It creates a small bump or bar at the base of the new stitch, which some knitters use as a design detail and others hide by working it on a purl row or in a seam.
Key Takeaways
- Knit front and back means inserting your needle into the front of a stitch, knitting it, then knitting the back of the same stitch before dropping it off the left needle.
- The stitch creates a visible bar or bump at its base, which sits directly below the new stitch on the right needle.
- This increase works the same way whether you are working flat or in the round, and on knit or purl rows.
- Knit front and back is faster than other increases like yarn overs or lifted increases, but the bar is more visible unless you hide it in a seam or purl row.
The Step-by-Step Motion
Insert your right needle into the stitch on your left needle from left to right, the way you would for a normal knit stitch. Wrap your yarn around the right needle and pull the loop through to the front — but do not drop the stitch off the left needle yet. This is the critical difference from a regular knit stitch.
Now insert your right needle into the back of that same stitch on the left needle. Go from right to left through the back loop. Wrap your yarn and pull a new loop through. Now drop the original stitch off the left needle. You now have two stitches on your right needle where you had one.
The whole motion takes about the same time as knitting two regular stitches, which is why KFB is popular for increases that need to happen quickly across a row.
Where the Bump Appears and Why It Matters
When you knit front and back, a small horizontal bar or bump forms at the base of the new stitch — directly below it on the right needle. This bar is the loop you created when you knitted into the front of the stitch. It is always there, and it is always visible unless you take steps to hide it.
If you are increasing at the edges of a sweater or in a seam, the bar disappears into the seam allowance and nobody sees it. If you are increasing across the middle of the fabric for a design detail, the bar becomes part of the pattern. Some knitters use this intentionally — the bars create a line of texture that looks deliberate.
If you want the increase to be invisible, work it on a purl row instead. The bump sits on the wrong side of the fabric and does not show on the front.
Knit Front and Back on a Purl Row
The same increase works on a purl row. Insert your needle into the stitch from right to left (the purl direction), purl it, and leave it on the left needle. Then purl into the back of the same stitch and drop it off. You end with two stitches, and the bump sits on the wrong side of the fabric.
This is the standard way to hide the increase if you are working flat and the bump would show on the front. The increase itself is just as strong and just as fast — only the direction of the needle changes.
Knit Front and Back in the Round
The motion is identical when you are working in the round. Knit into the front of the stitch, then knit into the back of the same stitch before dropping it off. The bump still appears at the base of the new stitch, in the same place.
In circular knitting, you cannot hide the bump on a purl row unless you switch to purling for a few rows. Many patterns that increase in the round use KFB anyway, either because the bump is part of the design or because it sits in a seam or edge that will be hidden later.
How Knit Front and Back Compares to Other Increases
A yarn over (YO) creates a hole and is completely invisible as an increase — you straightforward wrap the yarn around the needle. It is faster than KFB but leaves a deliberate eyelet, which works for lace but not for solid shaping.
A lifted increase picks up the loop from the row below and knits it, creating no visible bar. It is slower than KFB and takes practice, but the result is seamless. Many sweater patterns use lifted increases for this reason.
A make one (M1) picks up the strand between two stitches and knits it through the back loop. It is invisible and creates no bump, but it requires you to identify and lift a specific strand, which takes more precision than KFB.
Knit front and back is the fastest and easiest to execute, but the bump is the trade-off. Choose it when speed matters or when the bump will be hidden.
Common Mistakes and How to Avoid Them
The most common mistake is dropping the stitch off the left needle after the first knit, before you knit the back. This turns the increase into a regular knit stitch and you end up with the same number of stitches you started with. Slow down and make sure both loops are on your right needle before you move on.
Another mistake is knitting into the back loop incorrectly. The back loop is the one that sits away from you on the left needle. Insert your needle from right to left, not left to right. If you insert from the wrong direction, the new stitch will be twisted.
If your increases are uneven in size, you may be pulling the yarn too tight or too loose on one of the two knits. Keep the tension the same for both the front and back loops.
Frequently Asked Questions
Does knit front and back lean left or right?
KFB does not lean noticeably in either direction. The bump sits straight down from the new stitch. If you need a stitch that leans left or right for shaping, use a lifted increase or a make one instead.
Can I use knit front and back to increase multiple stitches in a row?
Yes. You can work KFB into every stitch across a row if a pattern calls for it, though this doubles your stitch count and creates a row of bumps. Most patterns space increases out — every few stitches or every few rows — to shape gradually.
What if I accidentally knit front and back but the stitch looks wrong?
Check that both loops are sitting on your right needle and that the original stitch came off your left needle. If the new stitch is twisted, you inserted the needle in the wrong direction on the back loop. Twisted stitches are still functional but look uneven.
Is knit front and back the same as a bar increase?
Yes. Knit front and back is sometimes called a bar increase because of the visible bar or bump it creates. Some patterns use the term "bar increase" to mean any increase that leaves a visible horizontal line.
Can I use knit front and back in ribbing?
Yes, but the bump will show more clearly because ribbing is textured. If you are increasing in a rib pattern, consider using a lifted increase or make one instead to keep the pattern clean.