How to Create a Custom-Fitted T-Shirt (Part 1)

I'm not a huge fan of t-shirts. They aren't flattering on me AT ALL. Also, ever since I got pregnant with Smasher, crew necks make me nauseous. I don't mean in some sort of fashion sickness, I mean literally. I feel like I'm being strangled.

But, recently, I have EARNED a few t-shirts, and I am determined to wear them. Which means making them palatable. There are a number of tutorials on the web for how to do this, but most of them require a t-shirt which you already own and like that you trace. I don't really have many that I like. I'd rather make one custom to my body.

So I'm starting, today, a series on how to create a custom-fitted t-shirt from an existing ill-fitting one. 

Part 1 will cover the side seams. This means creating a t-shirt that flatters your body. If the t-shirt you already have already has a comfortable neckline and the sleeves hit the top of your shoulder well, this is all you'll need.

Part 2 will cover the sleeves. If you have a way too-large shirt that needs the sleeves raised, here you go.

Alrighty, let's get started!

Part One: Side Seams

First off, you have to take some measurements. Measure across largest part of your bust, the smallest part of your waist (should be just an inch or two above the belly button) and across your hips (where the shirt hits you, or where you want it to hit you). There is a great illustration here that will show you where all these are if you need help. Make sure to take a deep breath on the chest and waist measurements. You don't want to wind up with something too tight. Now add at least an inch to each number. How much you add will depend on how form-fitting you want your shirt to be. I like mine pretty form fitting, so I add an inch, but if you want a looser fit, then add between 1.5 and 3 inches, or more. That is all preference. Then divide each number by four. If you get a decimal, round up to the nearest 1/4 inch.

For example, imagine these measurements:
Chest: 36 in + 1 = 37 / 4 = 9.25 inches
Waist: 29 in + 1 = 30 / 4 = 7.5 inches
Hips: 36.5 in + 1 = 37.5 / 4 = 9.375 => 9.5 inches

Now put your shirt on inside out. Using chalk or a fabric marking pen, draw a line on the front of the shirt in the center to mark your bust, waist and hip (if the hem of your shirt hits in a good place on your hip, it's not necessary to mark it). When you remove your shirt and lay it out (still inside out), it should look something like this:

Sorry my marks are a little hard to see.

 Now fold your shirt in half, making sure to line up the collar, shoulder seams and all four layers of seam sleeves. Smooth it out best as possible. Don't worry about the sleeves themselves, just make sure the seams are lined up. You should be able to see your marks. If your hem is a bit wonky, try to smooth it if possible, but sometimes t-shirts just have wonky hems because many are cut off-grain. I'll show you in Part 3 how to fix a bad hem. Mine here was a bit off, but only by a half inch, so I decided not to care.

 Now it's time to bring in those calculations from earlier. Line your ruler up with the middle fold of your fabric by the mark for chest like so, making sure the ruler is perpendicular to the folded edge of your shirt:

Then mark your calculation for chest at the end of the ruler. Repeat for your waist and hip marks, using your calculations. If you did not place a mark for your hip, then just make this mark at the hem.

Draw a line with a basic curve to connect these points. Make sure to connect the line up to the sleeve seam and down through the hem as well. NOTE: the line here on the blue shirt is not very good. You want the curves near the hip and chest to be a bit more modest. I had to even these out later. The side seam curve on the brown shirt below is a much better curve.

Then, using either good fabric shears or a rotary cutter, cut through all layers of fabric up to the sleeve seam. Do not cut into the sleeve yet. I placed pins through all layers next to the line before cutting to hold all the layers steady together.

Also a little note about sleeves: If your chest measurement is wider than your sleeve seam (like the brown shirt above) then just stop your cutting at the sleeve seam. Do not cut into the sleeve yet. I will show you how to re-size the sleeve in a moment. This tutorial assumes that the sleeve falls on your shoulders correctly so you don't need to reposition the sleeve, only re-size it. I will go over how to totally reposition the sleeve in Part 2. 
 
Unpin the edge and re-pin so that each side seam is pinned separately. I like to pin it so that I start sewing from the top of the garment for each seam (That's not how my pins are pictured here, though, sorry).

Now, unfold the shirt and smooth out one of the sleeves. Draw a line parallel to the existing seam on the sleeve from the point where your cut-line hits the seam to the hem of the sleeve. Like so:

Cut this line. Fold the shirt in half again and line up the sleeves (again paying particular attention to the sleeve seams and shoulder seams). Then trace this line onto the second sleeve and cut it as well. If you want, you can check the hem lengths of the sleeves to make sure they match.

Pin the sleeves separately then sew one seam down each side of the shirt, starting at the hem of the sleeves, using a 1/4 inch seam allowance. You can use a straight stitch if you like, because t-shirt fabric won't fray. I prefer to go down with a straight stitch, then stitch in the seam allowance with a zig zag stitch to secure it. You could, alternatively, use a zig zag stitch instead of the straight stitch, I've done that before, but in my experience, the stitches tend to pull apart a bit and reveal the string.

And you're done! Try it on!

This picture is after I evened out the curve that was under the armpit. I also made this to have a bit of a looser waist; I added 1.5 inches to the waist measurement. In Part 2, I'll show you a shirt made with 1 inch added. It's a bit more form fitting. 

Side note: I got this shirt at the Mud Run.