Convert a short-sleeve onesie into a long-sleeve T-shirt!

I discovered a curious thing about the children's clothing industry: apparently, babies age 3-12 months aren't allowed to wear T-shirts, unless they are purchased with the coordinating pants and hoodie ensemble. I discovered this as I combed through several large stores, thinking,  I just want a dang shirt! and finding that I had three options: squeeze Baby D into a 0-3 month shirt, let him swim in a 12-month shirt, or buy the shirt/pant combo and let the pants languish in a drawer somewhere.


I chose none of the above. And you don't have to, either! You can transform a short-sleeve onesie from this:

To this:

Here's what you'll need:

-Short-sleeved onesie
-Material for the sleeves. You can use any kind of knitted material: an old t-shirt, another onesie. I just happened to have some leftover knit fabric from another project. be sure the material is stretchy. Otherwise, it will fit really weird and Junior won't be able to bend his arms!
-Long-sleeved shirt or onesie to use as a pattern


(Sorry the pictures are such poor quality. My camera is currently broken, so I'm having to take photos with my cell phone! I hope to replace these pictures eventually.)


1. Lay the long-sleeved onesie out. Lay the short-sleeved onesie on top, with the shoulder seams matching. Measure the length difference in the sleeves. Also measure the width at the top of the sleeve, and the bottom. Add one inch to the length, and 1/4 inch to both widths.

For my six-month onesie, the dimensions (after adding the additional lengths) were seven inches long by 3-3/4 inches wide, tapering down to 3-1/2 inches. 

2. Fold your sleeve material in half. You want the knitting to be running up and down the fold, not across it. That way, the sleeves will stretch the right way. Cut two sleeves on the fold using your measurements. So, after cutting, my sleeves were 7 inches long by 7-1/2 inches wide, tapering to 7 inches.

3. On the short tapered end, fold up 1/4 inch onto the wrong side and sew with a zigzag stitch. This will be the end of the sleeve.

4. Fold in half, right sides together, and sew a 1/4 inch seam with a plain old running stitch. You now have a sleeve!

5. Turn the onesie inside-out. Pin the new sleeve, inside out, onto the onesie, matching seams. (As you can see, I like to use lots of pins!) You want the new sleeve to extend past the onesie sleeve hem stitching.

6. This was hard to photograph, so bear with me! You are going to be stitching on the outside of the onesie sleeve. Position the onesie on the sewing machine just so you are stitching through the neckhole onto the right side of the sleeve, but the rest of the onesie is inside-out. Using a zigzag stitch, sew over the hem stitching on the onesie sleeve.

All right! The hard part is over! You can stop here, if you just wanted long sleeves on your onesie. But if you still want a shirt, keep reading...

7. Cut across the onesie, just above the leg holes. This may seem like a long length for a shirt, but if you cut much shorter, you'll end up with a belly shirt-- especially if your baby has a longer torso. Trust me! If you still think it's too long after it's finished, you can just fold it up once more and sew that.

8. Fold up the bottom of the shirt about 5/8 inch onto the wrong side. Sew all around with a zigzag stitch.

Congratulations, you have a new shirt!

Evidently, Baby D doesn't like orange

This is a participating post on Works for Me Wednesday. Be sure to check out all the other great ideas floating around cyberspace!