Copy Your Favorite T-shirt – Simple & Easy Patternmaking Tutorial

Do you have a t-shirt that you absolutely love and wish you could just pop it in the printer to make a dozen copies of it in an array of colors and patterns? Well, you can (sort of) by making a pattern out of it! I’ll show you how to copy, measure, and true your favorite t-shirt pattern so that it’ll fit and hang the exact same way as your favorite t-shirt. I”ve also included how to make a long sleeve version as well. Let’s get started!

Things You’ll Need:

  • Paper – large enough to place your t-shirt on
  • Ruler
  • French curve
  • Curve ruler
  • Tracing wheel or pins
  • Tape

Youtube tutorial coming soon!


Draw a line and place the folded t-shirt against it. Be sure to smooth away any wrinkles or folds on the t-shirt. You can use some weights, sewing clips or pins, like I did here, to keep the garment in place. I like to use a ruler to press along the edges and keep them flat to trace the hem, side seam, and the shoulder.

A tracing wheel works well to trace the armhole but I prefer using a thin pin to poke along the armhole seam. Poke along the front neckline with a pin as well.

Most t-shirts have that twill tape along the back neckline and because my t-shirt was folded, I can easily flip the top half over and trace the back neckline using a pin.

Measure from armpit to armpit and the across the hem of the t-shirt, divide those measurements in half, and mark them on the pattern paper. 

The hem of my t-shirt also curves up towards the side seam and to find how by much, I simply placed my ruler on the folded garment at a right angle. My t-shirt’s hem curves up by 1/4” so I used my curve ruler to draw that on my pattern. I also used my curve ruler to smooth out the side seam. 

For the neckline – draw a straight line from the center line that’s about 3/8” and refine the front neckline using a French ruler. Use a curve ruler for the back. 

Measure the shoulder length of the t-shirt from the armsyce to the neckline seam and transfer that measurement to your pattern. Draw a short line about 3/8” straight down from the shoulder line and then use a curve ruler to refine the armscye. 

The back of my t-shirt “rolls” to the front by 1/4” so I drew in a new shoulder line that’s 1/4” from the previous one.

To make separate front and back bodice pieces, draw a straight line on another piece of paper, place the original pattern against it, and tape it in place. I added a 3/8” seam allowance to the armscye and side seam. I also cut away the excess top paper and then taped the top original pattern to the bottom paper. Then cut along the back neckline, the “old” shoulder line, the armscye, side seam, and hemline. The seam allowances for the neck, shoulder, and hem will be added later. 

After cutting out the front neckline, you’ll now have a front bodice and a back bodice. 

We still need to transfer that 1/4” from the shoulder so match the shoulders of the front and back pieces and tape it. Before cutting out the new shoulder seam, curve out any angles you might have along the neckline where the shoulders meet with a French ruler.

I added a 3/8” seam allowance to the neck and shoulder of the bodice pieces and 3/4” to the hem.


Start by drawing a straight line and another across it which is where the t-shirt’s armpit will be placed on.
Measure the length of the sleeve which is from the armpit to the sleeve hem and also do the same for the sleeve opening. Mark those measurements on the pattern paper.

Use a pin to transfer the sleeve cap. You can use a bendable ruler (this is my absolute favorite ruler from Dritz) or measuring tape to measure the length of the sleeve cap and make adjustments so that it matches half of the armscye’s measurement.

For example, 15 3/8” was the total measurement of my armscye so my sleeve cap needed to be half of that and I rounded it off to 7 5/8”. Because 1/4” from the front was put in the back bodice, the back’s armscye should be longer than the front’s. My front armscye measures 7 3/8” while the back’s is 8” so I measured 8” from the armpit, put a notch mark, and that will be the shoulder seam.  

Now that the short sleeve is done, we can easily do the long sleeve version while we are it. For the width, you can either measure one of the long sleeve garments you already have or grab a measuring tape and see how much you want the sleeve opening to be. Mine is 7 1/4”. My sleeve length is 18” so I divided the wrist measurement in half and marked it 18” down from the armpit and then connected the wrist to the armpit. 

Add 3/8” seam allowances to your sleeve except for the sleeve hem which is 3/4”.Then fold the long sleeve in half and cut it out. Now you’ll have one whole sleeve pattern.

My short sleeve’s opening is a little shorter than the long sleeve so I transferred it by folding the long sleeve pattern and placing it on another blank folded paper. You can either use a tracing wheel or pins to transfer the lines within the long sleeve and then by cutting along the sleeve cap. Don’t forget to add a 3/4” hem to the short sleeve. 

You should now have two lovely sleeve patterns.

Here are all the beauties!

And here is how I made the new favorite t-shirt using the pattern I just made.

*QUICK TIP If you have enough paper, I suggest making the bodice to one whole front and back pieces. I think it makes it easier to cut the fabric when it’s laid flat. Don’t forget to prewash your fabric!

Cut out all the pieces. Put the bodice pieces right sides together and sew only the shoulder seams with a zig zag, stretchy knit stitch, or serger. 

The neckband on my original t-shirt is 1/2” so I cut out 1 3/4” by 20” (which is my neckline’s total measurement) cross grain. See how to attach the neckband here as well as the no-math way to find out the length you’ll need to make a perfectly flat neckband.

Match up the sleeves to the bodice right sides together and sew with a stretchy stitch. 
Sew the side seams with a stretchy stitch.
The last step is the hemming. Fold up your hem – either use a small zig zag stitch, straight stretch stitch, or twin needles. I prefer using my twin needles because I can sew 2 rows at the same time and keeps the raw edge nice and flat.

TWIN NEEDLES TROUBLESHOOTING If your stitches are skipping it could possibly be one of these problems. 

  1. You’re using the wrong type for your fabric – some knit fabrics will let you use universal twin needles but for others you must use the stretch needles. Make sure your twin needles are stretch. Schmetz color codes their twin needles – the red is universal while the blue is stretch.
  2. One of the needles is dull – I agree that this one is hard to tell because I can never tell the difference until I put in new needles then I can see the difference in the stitches. 
  3. Are both needles catching the same layer of fabrics – sometimes if the left needle is too close to the raw edge or not catching enough of the seam allowance, it will start skipping. So make sure your seam allowance is wide enough to cover the feed dogs.
  4. Adjust the stitch length – the stitch length may be too wide so try shortening it.

My issue here was the stitch length. You can see what a huge difference it made by decreasing the stitch length just a little bit.

I painted a cute little Corgi inspired by Teddy and his “not today” mood. Lol. Isn’t he cute? Watch the snippet of the painting process on my Facebook and Instagram.

Thank you for staying with me to the end of this tutorial! I’ll be doing more tutorials on how to jazz up the favorite tee with ruffles, gathers, and turning it into cute dresses. 
Bye for now!

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