Baby Cardigan Onesie Tutorial

Learn how to make a baby cardigan onesie with a simple DIY tutorial. This baby sewing project is fun and easy to make!

Is your baby ready to be a trendy hipster, geeky nerd, or chic preppy? Choose your baby’s style with the new cardigan onesie style. Just take a long-sleeved onesie make a couple of snips and additions, and it’s a whole new style.

I’ll tell you how to do it in this simple baby cardigan onesie tutorial. I have updated and simplified this tutorial! You can see the new cardigan onesie tutorial or keep reading!

There are lots of fun details about this cardigan even though it’s fairly simple to make. It’s so fun to mix and match the colors and buttons.

I just love baby sewing projects!

It can be worn with or without pants or a skirt. It would be fun paired with a collared shirt, suspenders, and a bow tie. I would love to see it with a skirt and knee high socks for a little girl!

Update: I’ve had a lot of people have problems with the knit band or ask questions about it. The reason you multiply by .8 is so that the band does not gap or stretch out. 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. Also, use RIBBING and preferably with spandex to make your life a lot easier. 

Baby Cardigan Onesie Tutorial

supplies

• Long or short sleeved onesie- (I think the short sleeved ones look best on girls.)
• RIBBING (make your life easier by using ribbing with spandex!)
• Buttons or snaps
• Sewing tools and sewing machine
• Find the updated cardigan onesie tutorial here!
• Tips for sewing knit fabric

Instructions

If your onesie has crossover shoulders, find where the crossover lays flat and pin two layers together.

Sew with a straight stitch the two layers together so they don’t come apart.

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.

Cut on the line.

Draw from shoulders to parallel with the armpits.

Cut on lines up around the neckline so that you cut off the neck band.

This is perfect if there’s a small picture, phrase, or stain near the neckline that you want to get rid of.

Measure the whole length of the cut edge. Take the measurement and multiply by .8. 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.

Sew ends at 1/4″.

Turn right side out and poke out corners.

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.

Stretch each section and pin so the excess is distributed evenly.

Stretch while zigzagging at 1/4″.

Zigzag the edges of the snap facing to prevent fraying.

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.

Snap the snaps together overlapping the two sides.

Pin the two layers together and sew together.

Pin two layers of the front band together at three or four places. Sew buttons on at each pin.

Optional

Cut off sleeve hems. Measure length.

Take the measurement and multiply by .8. Add 1/4″ seam allowance. Use the same height as the front band.

Sew short edges to make a tube. Fold in half with right sides out.

Sew band to each sleeve end at 1/4″ stretching to fit.

With a straight stitch, stretch and sew the seam allowance towards the sleeve at 1/8″.

These baby boys are off to college in their new cardigan onesies.

If you make something using this sewing project, I’d love to see! Please share it on social media with the hashtag #heatherhandmade and tag me!