Convert an Oversized T-shirt Into a Workout Tank (With Pocket!)




Introduction: Convert an Oversized T-shirt Into a Workout Tank (With Pocket!)

About: Journalism and English student with a penchant for crafting. You can probably find me locked in my room, making something.

A while ago, I received an Instructables t-shirt from one of their prize packs, and for some reason, I realised too late that the large size was going to be way too big on me. This shirt has mostly spent its life (so far) inhabiting That Drawer With The Stuff I Don't Wear But That I Don't Want To Throw Out™, and I've been trying to think of a way to offer it a new life - that's what the Instructables robot would want, right?

I've recently started going to gym, and apparently some of the other people who work out there stick to similar schedules to me - and I'm starting to realise that if they miss me once or twice, they'll start thinking I only own one shirt (spoilers: I own, like, two, actually). Thus, I need a new workout top!

I really love one of the workout tops I have, as it has a nifty little pocket in the back where I can put my room key and music player. I wanted this convenience in my new shirt, too, so I based the idea for this shirt on the one I already had.

I added a hidden, zippered pocket in the back of the shirt, in which I could keep my essentials. I also added holes in the shirt to thread earphones through the front of the shirt, to the pocket in the back, allowing you to keep your music player tucked away in a pocket (and safe from being dropped by sweaty hands) and your earphone cable inside your shirt, rather than flopping about outside while you work out.

Finally, I completed the shirt with some reflective tape, for added visibility when I go running or when I'm walking to and from the gym!

I love the way this t-shirt transformation turned out, and I'm so happy I gave this shirt a second chance at life! Keep reading to find out how to convert your own unloved, oversized tee into a workout tank, too!

Here's what I used to upgrade my t-shirt:

  • a large t-shirt (thanks, Instructables!)
  • a zipper
  • some reflective tape/ribbon stuff
  • thread in the same colour as my shirt
  • iron-on interfacing

Step 1: Fitting the Top

I decided that my first step would have to be making the top more workout-friendly - the long sleeves and very baggy sides would have to go. I cut off the sleeves using a pair of fabric scissors, and simply pulled on the sleeve area to get the edges to roll back - I didn't feel like hemming all around the sleeves, and I don't mind the freshly-cut-shirt look for the gym. Set aside the fabric from the sleeves - you'll need this in a bit to make a pocket for the back of your shirt.

I also sewed a seam up each side, taking about 5cm (in total, so 2.5cm off the back and off the front) off each side, making the torso slightly more fitted - though you don't want to make it too fitted, as you'll still be adding a pocket in the back! I also shortened the shirt by 11cm, as I felt it was a bit longer than I wanted it to be. Obviously these measurements will vary based on how you want your shirt to fit.

While overlocking hems and seams may be preferable, the wonderful thing about knit fabrics, such as those t-shirt are made from, is that they don't really fray, and the edges curl back after they've been cut. This means that you don't need to overlock your seams and hems if you don't want to or don't know how.

Step 2: Making the Pocket Pattern

Next, determine how big you want the pocket to be. I wanted to be able to fit a cellphone or music player in mine, as well as my student card and Parkrun barcode. You'll want to double the size of the depth of the pocket, as we'll be folding it in half. I made my pocket 16cm by 24cm. This size included the size I wanted the pocket to be, with the depth doubled, as well as an additional 1.5cm on each side for a seam allowance. Also remember that you'll be adding a zipper to the pocket, so mark this out if you make a pattern like I did.

Cut your template from the fabric you set aside from the t-shirt sleeves.

Step 3: Making the Pocket: Zipper Opening

Once your pocket piece is cut, cut two strips from your iron-on interfacing, just larger than the zipper area will be. For me, this was 12cm by 2.5cm. Iron one onto the pocket, where the zipper is going to go, and the other onto the INSIDE of the shirt, where you want the zipper to lie.

The interfacing will make the fabric stronger and less likely to stretch. Draw the dimensions of the zipper opening onto the interfacing once it is ironed on.

Make sure that you iron the interfacing onto the t-shirt high enough so that the pocket will still be hidden by the back of the shirt.

When you've ironed on the interfacing, use a pen to draw on the zipper area dimensions.

Step 4: Making the Pocket: Attaching

1. Place the pocket and shirt back with their right sides together, interfacing facing outwards, and stitch them together around the box you have drawn onto the interfacing.

2. Ensure that the two pieces of interfacing are lined up exactly. Once stitched, you should have a small box stitched.

3. Use a small, sharp pair of scissors to cut down the middle of this box, and then cut into the corners.

4. Push the pocket through this hole and use an iron to press it.

Step 5: Adding the Zipper

You should now have your rectangular opening in the back of your shirt. Place your zipper into this opening, with the zip facing outwards when your shirt is the right way around, and use tacking stitches to secure it in place.

Using your sewing machine, sew around the edge of the zipper opening. Start stitching with the zipper closed, starting from the end without the zipper pull. When you reach the end of the zipper opening, leave your needle in the fabric, lift the foot of your sewing machine and unzip the zipper. With the zipper open, stitch down the other side of the zipper opening.

Remove the tacking stitches and trim off any remaining threads.

Step 6: Adding Earphone Holes

Because I wanted the pocket to be able to hold a music player, it makes sense for that music player to be accessible. To do this, I added a button hole in both the front of the top, on one shoulder, as well as in the back pocket.

Iron a small piece of interfacing onto the side of the pocket that will be hidden when it is closed, which should currently be facing outwards when your shirt is inside out (am I making sense? I'm not sure).

Use your sewing machine's button hole function to stitch a button hole on this piece of interfacing. Repeat this step on the shoulder nearest to the hole you just made, and then use a small, sharp pair of scissors to cut the button holes open.

Step 7: Closing the Pocket

Turn your shirt inside-out, so that the pocket is easily accessible. Flip the bottom of the pocket up, and line the bottom corners up with the top corners, just above the zipper. Pin these pieces into place and stitch around the three pocket edges using the sewing machine.

Once you've stitched around the edges, trim off the threads, and your pocket is complete!

Step 8: Adding Reflective Tape

Finally, I added some reflective tape/ribbon to my shirt. The tape I had was quite thick, so I cut a strip in half, though I found that was still too thick for the width I wanted. I ended up using it at a quarter of the width, and I added a strip down each side of the front of the shirt, at a diagonal angle. I stitched these strips on using my sewing machine. I'll probably also add some more strips at the back when I have a chance.

Naturally, you can add this tape anywhere on the shirt and in any design, and it really adds to visibility if you're running in the road!

Step 9: Threading in Your Earphones

To tuck your earphones into your shirt, first thread them through the button hole near the shoulder. Next, thread them through the hole in the pocket. Open the pocket to pull it through, and plug it into your music player, et voila! Your music player and earphone cables are neatly tucked away for your workout!

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    7 Discussions


    4 years ago

    Noice. I fully agree about the tack and ironing.

    My first couple of projects, I didn't bother, thinking it was a nice but not essential.

    Now, I tack and iron everything.

    bhavik zure
    bhavik zure

    4 years ago




    Reply 4 years ago

    Awesome, thank you. :D


    4 years ago

    That looks totally professional. I'm impressed with your sewing skills & creativity! Thank you for sharing!


    Reply 4 years ago

    Thank you so much! I swear, tacking things in place before stitching them and ironing things properly makes all the difference with sewing and making things look more professional. :) And it's always a pleasure to share with a creative community!


    Reply 4 years ago

    Awesome, thank you so much! I really appreciate it!