Is your baby ready to be a trendy hipster, geeky nerd, or chic prep? Choose your baby’s style with the new cardigan onesie. Just take a long-sleeved onesie make a couple of snips and additions, and it’s a whole new style.
I have updated and simplified this tutorial! You can see the new cardigan onesie tutorial and a baby girl wearing a cardigan onesie!
Baby Cardigan Onesie Tutorial

There are lots of fun details about this cardigan even though it’s fairly simple to make.

Baby Cardigan Onesie Tutorial
It can be worn with or without pants. Or a skirt for girls. It would be fun paired with a collared shirt, suspenders, and a bow tie.
Baby Cardigan Onesie Tutorial
Update: I’ve had a lot of people have problems with the knit band or ask questions about it. The reason you multiply by .75 is so that the band does not gap. When you cut the onesie and then sew a seam, it will stretch. By using a slightly smaller band, it will counter the stretching out and make it lay nicely. You could also use .85 if you’re more comfortable with that. Also, use RIBBING to make your life a lot easier. Ribbing stretches well and doesn’t shrink. Supplies

Long or short sleeved onesie- (I think the short sleeved ones look best on girls.)
RIBBING (make your life easier by using ribbing and not regular knit!)
1. If your onesie has crossover shoulders, find where the crossover lays flat and pin two layers together.
2. Either zigzag or double needle the two layers together.
Baby Cardigan Onesie Tutorial
3. Measure across the front of the onesie and mark the center all the way down. At the bottom slant to one side between two of the snaps.
Baby Cardigan Onesie Tutorial
4. Cut on the line.
5. Draw from shoulders to parallel with the armpits.
6. Cut on lines up around the neckline so that you cut off the neck band.
Baby Cardigan Onesie Tutorial
*This is perfect if there’s a small picture, phrase, or stain near the neckline that you want to get rid of.
Baby Cardigan Onesie Tutorial
7. Measure the whole cut edge. Take the measurement and multiply by .75. Add 1/4″ seam allowance. This is the length of the front band. I wanted my band to be 3/4″ tall, so double that amount and add 1/4″ seam allowance. Make sure the stretch goes with the long sides.
8. Sew ends at 1/4″.
9. Turn right side out and poke out corners.
Baby Cardigan Onesie Tutorial
10. Find the center of the band and then the center of each side, so you divide the band into four sections. Use the same method to divide the cut edge of the onesie into four sections. Match pins.
Baby Cardigan Onesie Tutorial
12. Stretch each section and pin so the excess is distributed evenly.
13. Stretch while zigzagging at 1/4″.
Baby Cardigan Onesie Tutorial
14. Zigzag the edges of the snap facing to prevent fraying.
Baby Cardigan Onesie Tutorial
15. With your machine set on to a straight stitch, stretch and sew the seam allowance towards the onesie. Sew at 1/8″. Careful when going over the shoulders.
Baby Cardigan Onesie Tutorial
16. Snap the snaps together overlapping the two sides.
17. Pin the two layers together and sew together.
Baby Cardigan Onesie Tutorial
18. Pin two layers of the front band together at three or four places. Sew buttons on at each pin.
Baby Cardigan Onesie Tutorial
19. Cut off sleeve hems. Measure length.
20. Take the measurement and multiply by .75. Add 1/4″ seam allowance. Use the same height as the front band.
21. Sew short edges to make a tube. Fold in half with right sides out.
Baby Cardigan Onesie Tutorial
22. Sew band to each sleeve end at 1/4″ stretching to fit.
23. With a straight stitch, stretch and sew the seam allowance towards the sleeve at 1/8″.
Baby Cardigan Onesie Tutorial
These baby boys are off to college in their new cardigan onesies.
Baby Cardigan Onesie Tutorial
You can play a pick up game of soccer
Baby Cardigan Onesie Tutorial
or just have some laughs with your friend.
Baby Cardigan Onesie Tutorial

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Author: Heather Handmade

I'm a seamstress and mother. I sew, blog, thrift, upcycle, design fabric, and teach sewing classes. I'm also a self-proclaimed fabric fondler.

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56 thoughts on “Baby Cardigan Onesie Tutorial

  1. It can be worn with or without pants. Or a skirt for girls. It would be fun paired with a collared shirt, suspenders, and a bow tie. maquinas de coser

    Posted on January 11, 2016 at 6:48 am
  2. I love this idea!! Do you think you could use snaps instead of buttons and button holes?

    Posted on May 2, 2014 at 3:30 pm
    1. You definitely could!

      Posted on May 5, 2014 at 3:46 pm
  3. This is awesome!i can't wait to make an old man cardigan out of a onesie for my oversized 1 month old boy! I've just pinned this and someone posted a pic of their own version in the peek a boo patterns Facebook group.
    P.s. Congrats on your new baby!

    Posted on March 22, 2014 at 5:16 pm
  4. Lol.. I saw this on Pinterest and I was like isn't that so-and-so's baby? Then I saw the background of the photos 🙂 we used to live in the 800 court 🙂

    Posted on July 7, 2013 at 2:21 am
  5. Do you mind my asking where you found the ribbing? I've looked at all the local fabric stores and can't find anything similar.

    Posted on March 8, 2013 at 8:32 pm
    1. I know joann's definitely has rib knit. Hancock's doesn't. You'd be able to find rib knit most places online. You could even buy used sweatshirts to use the ribbing from the hem and the sleeves.

      Posted on March 9, 2013 at 2:49 pm
    2. I could NOT get the rib knit at Joann's in Nashville TN> I had to go to a speciality store!!

      Posted on August 8, 2014 at 11:02 pm
  6. Posted on February 26, 2013 at 3:45 pm
  7. I am getting ready to make this for a friend, and I just wanted double check, the buttons are not actually functional correct?

    Posted on February 5, 2013 at 6:36 pm
    1. That's right! They aren't needed!

      Posted on February 5, 2013 at 7:47 pm
  8. I found that if I multiple the measurement by .80 works better than the .75. Too much puckering when I use good rib knit. I also have a tool that takes off the snap and my husband straightens the prong out so I can reuse it, so I cut it straight down. I didn't like the angle cut especially on the smaller sizes.

    Posted on January 30, 2013 at 4:18 am
  9. I am interested in making these to sell. I don't want to steal your idea or anything so am asking permission. I will be using this tutorial ( in addition to yours but wanted to check with you as far the the permission to use parts of your tutorial to make my items. I see you have given another etsy store permission to sell also. Thanks so much!

    Posted on January 26, 2013 at 10:25 pm
  10. Hello, I just wanted to say I love this idea and tutorial, I hope you don't mind but I posted it on my blog at with the link to your page. I think moms everywhere need to see this!

    Posted on January 18, 2013 at 8:38 pm
  11. I just made this last night. So easy one I figured it out! Thank you for the tutorial, I appreciate it. I'd post a photo if I could.

    Posted on January 12, 2013 at 2:56 pm
    1. Email it to me, and I'll post it on the facebook page and feature you!

      Posted on January 13, 2013 at 12:17 am
  12. Heather,

    LOVE this tutorial!! Just made my first one last night and your tutorial was great! Question though, I had a really hard time with the border and getting my knit to stretch enough (it worked, was just SUPER difficult to stretch and feed and sew straight), so I'm wondering what would happen if I didn't multiply by .75? THANKS!!

    Posted on November 21, 2012 at 11:12 am
    1. Yay! I'm so glad you made one! I've had a lot of people asking about the knit and having problems with it. The reason that the band is smaller than the body piece is because if it's the same length, the seam will stretch out the area and the band will gap. All knit cardigans do this even though you can't see it.
      It will be a lot easier to use ribbing because it stretches well without shrinking. Or multiply by .85 instead.
      I hope that helps!

      Posted on November 21, 2012 at 2:23 pm
  13. Oh my word this is adorable!

    Posted on November 16, 2012 at 4:25 am
  14. So cute! And excellent tutorial!

    Posted on November 8, 2012 at 8:19 pm
  15. This is so adorable!!! Thank you for sharing this tutorial can't wait to make one!

    Posted on October 26, 2012 at 2:07 pm
  16. Thank you so much for this tutorial! I used it to make a few for some friends having baby boys in the next few months.

    Posted on October 25, 2012 at 7:37 pm
  17. Hey Heather, I'm about to try to make one this weekend! I have a question, and it may seem stupid, but still. Where did you get the knit fabric for cuffs and border? Joanns? I've never bought knit fabric before. Thanks!

    Posted on September 21, 2012 at 3:29 pm
  18. Go to to purchase one!! More colors and patterns are added daily. Thanks Heather!!

    Posted on September 19, 2012 at 6:33 am
  19. can't wait to get started….my daughter in law sent this post to me two times so I think I'm getting the hint!!!!!!

    Posted on September 16, 2012 at 1:56 pm
  20. Your tutorial is SO clear! Thank you! I can't wait to try these as gifts.

    Posted on September 13, 2012 at 1:06 am
  21. Love this Heather! You are so creative and talented!

    Posted on September 12, 2012 at 8:52 pm
  22. How cute is this!!! LOVE LOVE LOVE.

    Posted on August 29, 2012 at 1:02 pm
  23. Did you multiple by the .75 for the orange and gray cardigans too? They don't look gathered like the gray striped one but it could be because the boys are wearing them. Love the tutorial and can't wait to make some for my little guy. Thanks so much!

    Posted on August 27, 2012 at 1:31 am
    1. I did multiply by .75 for the orange and gray cardigans you just can't see it while the boys are wearing it because the fabric gets stretched out.

      Posted on August 27, 2012 at 7:48 pm
  24. Heather, will you let me know if you would be willing to sell one?

    Posted on August 26, 2012 at 12:13 pm
  25. Any ladies selling in etsy. Or selling period . I have to havesome from my lil guy!!

    Posted on August 21, 2012 at 12:40 am
    1. Not that I know of. I own the creative rights and haven't had anyone ask. I'm also currently not making and selling any.

      Posted on August 21, 2012 at 12:58 am
    2. I don't sew, but would love to buy some!

      Posted on August 26, 2012 at 12:31 pm
  26. Where did you get the caterpillar rocking horse?

    Posted on August 20, 2012 at 11:21 am
    1. I got it at a yard sale in my apartment complex.

      Posted on August 20, 2012 at 12:11 pm
  27. Adorable!!!!!

    Posted on August 20, 2012 at 7:04 am
  28. You are a GENIUS!!! I love this and will be trying this for the grandkids!

    Posted on August 19, 2012 at 12:59 pm
  29. You are a GENIUS!!! I love this and will be trying this for the grandkids!

    Posted on August 19, 2012 at 12:59 pm
  30. This is soooo adorable! What a fantastic idea. Love!

    Posted on August 19, 2012 at 7:09 am
  31. Babys look so cute!!!! Thanks for the tutorial!

    Posted on August 18, 2012 at 10:03 pm
  32. LOVE this! My little man definitely needs one of his own.

    Posted on August 18, 2012 at 5:04 am
  33. In that last picture he looks like Calvin from Calvin and Hobbes.

    Posted on August 18, 2012 at 1:25 am
  34. oh my goodness! super cute idea. I hate sweatshirts for little boys because they ride up, but this would totally stay in place.

    Posted on August 17, 2012 at 9:21 pm
  35. amazing!! I love it!

    Posted on August 17, 2012 at 8:53 pm
  36. This is so cute Heather! I might try it for James 🙂

    Posted on August 17, 2012 at 8:50 pm
  37. This is awesome. I love it. Your creativity never ends.

    Posted on August 17, 2012 at 8:34 pm
  38. super cute! how long did this take you?

    Posted on August 17, 2012 at 8:01 pm
    1. I've made three so far, and get faster each time, but they probably take an hour or less. It's hard to say because I take so many breaks!

      Posted on August 17, 2012 at 9:25 pm
  39. What a great idea! And a great way to continue to use the cute onesie even after they get stained. Thank you, you are amazing!

    Posted on August 17, 2012 at 3:07 pm
  40. HOW CUTE!!! Definitely pinning this.

    Posted on August 17, 2012 at 2:44 pm
  41. that is so cute! What a genius idea!

    Posted on August 17, 2012 at 2:37 pm
  42. Super duper cute! I'm very impressed Heather! If you keep up all these tutorials I might be inspired to invest in a sewing machine! Way to go!!!

    Posted on August 17, 2012 at 2:35 pm
  43. OH. MY. GOODNESS HEATHER!! !I AM DYING!! This is simply FABULOUS!!! Love it so much!!! Pin pin pin pin pin pin pin

    Posted on August 17, 2012 at 2:24 pm