Beginner Sewing Project: Sweatshirt Midi Dress with Side Slit

Outfit Details:

Sweatshirt Dress (made by me – similar HERE and HERE), Ecco Sneakers, LA Dodgers Hat, Similar Leather Tote Bag, Similar Bandana

Time for another beginner sewing tutorial! If you missed the one last month, you can find it HERE. I’ll be sharing a new beginner sewing project every month, so those of you just learning to sew can confidently create some amazing pieces!

Today’s sewing project is a long sleeve midi dress with a slit on the side. There are no darts, no zipper, and no waistline, so it’s quick and straight forward!

I dressed it down with a baseball cap and sneakers, but I’ll be showing you later this week how to dress it up.

sweatshirt dress and baseballl cap
an easy DIY sweater dress
gray midi dress

midi sweater dress
a midi dress and a pair of simple sneakers makes a great weekend outfit

Ok, let’s get down to the tutorial. If you’re brand new to sewing, check out my ONLINE SEWING COURSE right HERE. It’s all the basics, from how to turn your sewing machine on up to creating neckline and sleeves and more. It’s an amazing resource.

But for this tutorial, you really can be a beginner and pull it off.


1 1/2-2 yards sweatshirt fleece material (something like this would be great. I got my quilted sweatshirt fleece fabric at my local JoAnns)
Matching thread (use an all purpose thread – I like Gutermann brand)
Sewing Machine
Iron + Board
T-shirt/Tank, or Shift Dress(to use as a pattern)
Pattern Paper (optional, but recommended. I use THIS)

A beginner sewing tutorial for this cute midi sweatshirt dress

Creating Your Pattern

If you’re new to creating patterns, I have a free video on the Modern Girl Sewing YouTube channel that walks you through how to create a pattern using your own clothing as a guide. Use those instructions to create your pattern. You’ll need pattern pieces for a DRESS FRONT, DRESS BACK, LONG SLEEVE (cut two of these), and NECKLINE LINING (you’ll need a back and front piece).

For the DRESS FRONT and DRESS BACK, they should be identical except for the neckline. Make the front neckline lower by about an inch or two, as show in the illustration.

For the SLEEVES, you can make them any length you want. Just cut them shorter to make them half or short sleeve.

For the NECKLINE LINING, cut pieces that are identical to the necklines of the DRESS FRONT + BACK. Make them about 2″ wide, as show in the illustration.

Cutting out your pieces

Lay your pattern pieces flat on your fabric. Make sure the direction of the fabric’s stretch is across your hips and bust, as shown in the illustration.

Pin your pieces to the fabric and cut around them, adding about 1/2″ of seam allowance to each side.

You should have six cut pieces (2 DRESS pieces, 2 SLEEVES, and 2 NECKLINE LINING pieces).


Step by step instructions

Step 1. Take your DRESS FRONT and DRESS BACK pieces and pin them together at the shoulders. The right sides of the fabric should be facing each other. Sew across the shoulders with a 1/2″ seam allowance (ie. 1/2″ from the edge of the fabric).

Step 2. Take your NECKLINE LINING pieces and pin them together on the shoulder seams with right sides of the fabric facing each other. Sew across each side with a straight stitch and a 1″ seam allowance. Note: you need a bigger seam allowance here because you’ll need to stretch it in the next step and you need it to be slightly smaller than your dress neck hole. Now your lining will be in the shape of an “O.” Trim off the extra seam allowance.

Step 3. Now take your NECKLINE LINING and DRESS pieces and (with right sides of the fabric together), line up the lining directly over the neck hole of the dress. Line up the shoulder seams on either side and pin in place. Now stretch the LINING slightly to evenly pin it around the DRESS neck hole. Once it’s pinned all the way around the opening, sew around the entire opening with a straight stitch and a 1/2″ seam allowance. Note: As you sew, you’ll have to stretch the neckline slightly to get the LINING to lay flat with the DRESS in between pins. But DO NOT stretch more than that or your neckline will be wavy!

Step 4. Once the NECKLINE LINING is attached to the dress, trim your seam allowance (or serge or zigzag it) and then tuck the lining inside the dress. Pin it in place and then sew around the entire neckline with a straight stitch to hold the LINING in place.

If your neck hole is large enough for your head to go through, you can do a regular straight stitch (just turn your stitch width up to like 4.0 — shorter stitches will make your neckline wavy too!). If you need some stretch to fit your head through, use a double needle and do a double stitch around the neckline to allow for some stretch.

Step 5. Now it’s time for sleeves. Take your DRESS and lay it open flat, right side of the fabric up. Line up the top of the shoulder curve of the SLEEVE with the shoulder seam of the DRESS (right sides together), as shown in the illustration. Pin in place. Now pin down both sides of the shoulder curve, pinning the SLEEVE to the DRESS.

Step 5, continued. Once it’s pinned, sew them carefully together, up and around the curve. Repeat for the second SLEEVE on the other side.

Step 6. With right sides of the fabric together, pin the dress from wrist to armpit, and armpit to hemline. Make sure those armpit seams are matched up. Then sew from wrist to armpit to hemline with a straight stitch. Repeat on the other side, but stop when you get about 10″ from the hemline (we’re leaving it open for the slit).

Step 7. Now for the slit. Press open your seam allowance on the side seam of your dress and pin the remainder of the seam allowance down each side of the slit. Then sew with a straight stitch up one side of the slit, across the top, and down the other side, stitching that seam allowance in place.

Step 8. Now fold the end of your sleeves up twice and stitch around the opening (use a double needle again if you need some stretch!), and do the same for the hemline of the dress.

Step 9. Press all your seams flat with a hot iron and you’re done!



this midi sweatshirt dress is a perfect beginner sewing project. No zippers, no darts -- you can do it!

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  1. Natali says:

    I love wearing sweatshirt dresses in winter and this is such a perfect diy dress! wow!

  2. Helen says:

    I’m so glad that this dress is beginner friendly because I need it in my closet. It’s so cute and versatile!


  3. Lindsey says:

    Hi Merrick, I voted for DIY Fridays buuuut actually love reading this on a Tuesday and being able to think ahead about a weekend project! Who knew?! Really cute dress!!

  4. Alice says:

    This is exactly the kind of tutorial I hoped for! I love your ILLUSTRATed instructions, and I love beginner sewing projects that aren’t boring aprons and circle skirts, but something I’d really want to wear! Excited for more of these 🙂

  5. Meg says:

    Love this tutorial, but as a beginner sewer, I think a short video would be helpful too! I kind of got lost in the steps 🙁

    • Merrick says:

      That’s good feedback! I’m not sure I’ll ever get to the point where I can do videos AND illustrations AND written step by steps in one post, but I appreciate the insight!

    • Merrick says:

      Oh, but I do have the videos on my guides if you want to work on those to build up your sewing skill set!

  6. Anna Lena says:

    I love sweatshirt dresses!! I’m so happy you’re sharing a tutor for it.

    IF you wanted to add darts at the front, do you have to use more fabric in the BEGINNING for the front piece? And how much more?

    I really like your sewing tutorials on any day. For me they don’t have to be on Fridays or any specific days.

    • Merrick says:

      You’ll need to add a little extra on each side where the dart will go. Like a slight point on each side at the bust – maybe like 1″ out on each side. That’s the only difference!

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