How to KFB – knit front back

A step-by-step tutorial on knitting KFB. An easy left-slanting increase for beginners.

So, your pattern tells you to increase with KFB and you have no idea what it means and how to knit it? Well, you came to the right place. In this tutorial, I’m going to show you exactly how to KFB.

A swatch with kbf knitting increases
A swatch where I increased with KFB on the right side and the more invisible KFSB on the left side

What does KFB mean in Knitting

The abbreviation KFB stands for “Knit front back” and refers to a popular knitting increase where you knit twice into the same stitch – once through the front of the loop and one more time through the back loop of the same stitch. It is also known as “Bar Increase” because you’ll create a little visible purl bar with it. Sometimes is also abbreviated as “K1fb” or even “K1f&b”.

The resulting increase leans towards the left (so just like M1L) and is quite visible in stockinette stitch due to the little bar. Further down below, I’ll show you a variation of the KFB without the bar. The right-leaning counterpart is called SKL – slip, knit, lift. The purl equivalent is pfb – purl front & back.

So, let’s show you how to increase with knit one front and back:

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close-up of a green swatch increases with kfb (knit front back) and kfsb

This stretchy bind-off works similar to the standard method. But instead of passing stitches over, you knit them together. Plus, you have to bind off in pattern. Meaning you knit all knit stitches and purl all purl stitches.

Active Time 1 minute
Total Time 1 minute


  1. Knit one stitch (so, just do a normal knit stitch) AND DON’T slip it onto the right needle.

    knit one stitch for the kfb increase
  2. Insert the needle into the back loop of the same stitch from right to

    insert needle into the back loop of same stitch
  3. Wrap the yarn around your needle counter-clockwise and pull the yarn through and drop the stitch.

    Knit into the same stitch through the back loop

And there is your KFB. It’s really that simple. Essentially you are combining a regular knit stitch with a knit through the back loop (ktbl) into the same stitch - hence the name.

kfb knit front back on right needle

KFSB – Knit front, slip back

So, you don’t like the little bar / bump the KFB creates and you are wondering if there is a way to avoid it? There are plenty. The most invisible left-slanting increase for stockinette stitch is probably KLL (Knit through left loop). But if knitting into a stitch two rows below sounds a bit too complicated to you, you can achieve a similar result called KFBS – the abbreviation for knit front, slip back.

close-up of a green swatch increases with kfb (knit front back) and kfsb
KFSB on the left side and KFB on the right side.

Instead of knitting the second part of the increase through the back loop, you only slip the back loop onto your right needle. Here is how:

Step 1: Knit one stitch and don’t drop it off your left needle (so just like before).

kit one for knit front slip back

Step 2: Insert the needle in the back loop of the same stitch.

insert needle into the back loop of same stitch for kfsb

Step 3: Slip it onto your right needle WITHOUT knitting it through the back loop.

knit front slip back on the right needle

And that’s it. It’s even simpler than the KFB and quite a bit less conspicuous. You will see the tiniest little eyelet but as long as the portion of the fabric is not put under stress, you won’t really be able to see it.

Note: In patterns, where knit stitches are followed by purl stitches (like Moss Stitch, etc) this increase can be a very good and invisible option. The little bar can be a bonus as well, don’t just think of it as something to avoid!

Knit back and front

Another variation of the KFB is the KBF, knit back and front. You can probably already guess how to knit it. You knit through the back loop first and then, in a second step, you knit a regular knit stitch into the front loop of the same stitch. Otherwise, it’s exactly the same knitting technique.

This will result in one twisted knit stitch on your needle and a slightly smaller bar. For an untwisted version, you could slip the stitch before you knit through the back loop first. So, slip 1 knitwise, slip the stitch back to the left needle, and only then ktbl.

So, this was my tutorial on how to do a KFB in knitting increase. Please leave a comment if you have any questions!

how to knit kfb (knit front back)

13 thoughts on “How to KFB – knit front back”

  1. Hi there.
    Re: KFB, does it matter when knitting the 2nd part of the stitch (through the back loop of the stitich), if you loop the yarn clockwise or counterclockwise? Does that affect the overall look? I am knitting a dog sweater that uses KFB, K, KFB down the middle of the chest. It is supposed to create a nice, even-looking pattern, flaring out as it goes further downward on the chest. However, my KFB stitches sometimes flare outward (from the middle K-only stitch) and sometimes flare inward. I’m not sure what I am doing wrong. Thanks.

    • Hey Carla,
      yes it absolutely matters if you knit through the back loop first or second. Stick to back according to your pattern! If you don’t like the way it looks, you can easily exchange it for a backwardloop increase or possibly even a lifted increase.

      • that’s not what she asked though, she asked about the direction you wrap the yarn while making the stitch.

        i also wanted to know this! i’m left-handed so i have to work out exactly what’s happening in any stitch so i can mirror it effectively.

  2. Hi Norman, I’m a new knitter. I tried making this increase, but found that either the back part of the KFB was too tight to get the stitch off onto my needle, or I could get it off, but then next row was too impossibly tight to knit. I even tried it on the first row of a long tailed cast on around 2 needles so that the initial stitch that I was KFBing into was super loose, but still the same problem. How can I avoid this? Thanks for your wonderful tutorials!!

    • Very difficult to tell, Nadine. WHat you can try is, when you knit the first stitch, make it much looser, and then, when you knit into the backloop, don’t pull as tight. Otherwise, try the alternative version I show further down where you only slip the second stitch.

  3. Thanks for mentioning that KFBS stands for knit front, slip back. I’d really like to start knitting so I can have gifts for my family this Christmas. I think it would be really fun to be able to create handmade gifts and pick up a new skill.

  4. Hi Norman,

    Thanks for perfect tutorial!
    I started to knit about 1 year ago, before I only did crochet projects. What I struggle with if it comes to KFB is very loose first stitch. Unlike Nadine above, the second one is perfectly fine, just this first one becomes soo loose, even if I try too pull the yarn stronger, what’s harder for more fuzzier yarn.
    It’s making me crazy while doing a reglan increases in up-down sweaters.
    Do you have some tips how to avoid this?


  5. As always, Norman, you explain things so well and your pictorial demonstrations are fantastic. Even though I am not knitting any project at the moment, I just love practicing stitches and techniques.

  6. Hi Norman!

    Your website is fantastic! It’s the first place I check when I need to do something different. When I first started knitting there was no internet, so I have a lot of books. I still love my knitting library, but this is so much easier. I wanted a way to KFB without the bump, and KFSB solved this, how simple! Isn’t that the way it usually is? Thank you for all your effort! Cindy


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