Turning your Onesie into a Dress

Hi! It’s Esther Lewis here! I’m talking about the Mamma Can Do It Onesie today. I don’t know how you decide what to sew for your babies, but I love convenient and cute all in one. One of my favorites for my baby girls are the little onesie dresses. I had searched around a little bit and was never able to find a pattern. I finally just told myself, “You can figure out how to hack the MCDI onesie on your own!” Sometimes the only reason we can’t do something is because that’s what we’ve told ourselves. So today, I’m going to show you how to make an adorable onesie dress with a little bit of a capped sleeve.

First of all, if you don’t have the pattern, Grab it here! MCDI Onesie. The links I use throughout this post are affiliate links, and I’d love if you chose to click on them if you need to shop! ?

I’ll show you how to prep your pattern, and then walk through the sections that we are going to switch up



Step 1.

We’re going to need to change the shape of our sleeve cap to be able to gather it a little. Start with your desired size.

I prefer to trace the size I’m using off of a master copy of all sizes. You can also print ONLY the size you need in layers in Adobe. I used 9-12 month for my little munchkin. Draw a line straight across your sleeve to the top edge of where your sleeve starts curving. Cut it off but keep it for our next step.

Step 2.


Lay your sleeve on top of another piece of paper. Make an angle opening toward your fold edge. The higher you tilt your piece, the more gathering you will end up with. Draw a line straight up from your sleeve to the top of your new cap. (Yellow line) and trace down over your original sleeve cap. You may want to do a practice run on your sleeve. My first version was not quite as much gathering as I wanted, so I followed my steps and tilted it back even more.

Step 3.

Mark your sleeve where you will start your gathering. (Remember this mark will be on both sides of the sleeve because it is cut on the fold.)

(Original cap vs. New Cap)

Now your new sleeve pattern is all ready!


Step 1.

Measure across your front bodice.

Double your number to account for the fold. Multiply by 2. My bodice was 5” across, so I want the width of one skirt piece to be 20”. I’ll be cutting two of these. (One for the front, one for the back) The amount of gather is preference. I like the look of double the width gathering. ?

Step 2.

Measure down on your bodice piece where you would like your dress to start. You can choose between a higher waistline or lower. I like my waistline a little higher so I measured down 2 1/8” on the 9-12 month front bodice. Draw a straight line across your piece. Mirror this line on to your back bodice piece being careful that they are the same length down from each pit.

Step 3.

Measure down from your waistline. I wanted my skirt to hit mid thigh, so I measured 8” down. Account for seam allowance (3/8”) and dress hem (I chose 1/2” and you end up with 8 7/8” for your width. Summed up, that means you will need to cut two skirt pieces 8 7/8”W X 20L.

Step 4.

Cut apart your front and back pieces on the lines you drew. You are ready to cut out all of your pattern pieces now! When you are cutting out your front and back pieces, don’t forget to add 3/8” to the top and bottom pieces to account for your new seam!


Step 1.

Get all of your pattern pieces cut out and start your project per instructions. When you are ready to add your sleeves, sew a gathering stich in between your marks and gather your sleeve to fit your armscye. Attach your sleeves as the pattern instructs.

Follow the instructions for sewing the sides. Your dress should look like this now.

Step 2.

Sew down the sides of your bottom onesie front and bottom onesie back RST (Black lines.) Turn right side out.

Lay your skirt pieces RST and sew down the sides.

Step 3.

Gather your skirt using your preferred method and pin around the bottom half of your onesie. You can choose to baste here if desired. Turn your top piece inside out and pin RST around your gathered skirt and bottom half of onesie.

Sew together. Flip it Right side out and you are ready to finish your MCDI Onesie dress by following the rest of the pattern instructions!

It should like like this! 🙂


That wasn’t as bad as you thought was it? Your dress should look something like this when you are finished.

And your baby will probably be as happy as mine when you put her in it.

I would love to see any MCDI Onesie Dress creations you come up with! You can share them in the Mamma Can Do It sewing group on facebook!



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2 thoughts on “Turning your Onesie into a Dress”

  1. Pingback: Week Before Easter Sewing – Momma Amidst a Sew

  2. Pingback: Turning Your Onesie into a Baby Gown | Mamma Can Do It Sewing Blog

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