It doesn’t fit me awful, but it’s about 4-5 inches too big around in the stomach
and throughout the rest of the torso (albeit not as bad). It’s also too baggy in the arms
We’ll fix that at the same time. Ultimate, we are going to replace the entire seam along the side of the shirt
The existing seam is called a ‘flat felled seam’. It’s fairly complicated to make, and trying to ‘tie into it’ would never look quite right, so I’m just going to replace the whole seam with a simple straight stitch.First put on the shirt, and using a tailor’s tape (those flexible measuring tapes tailors use to take measurements) measure the circumference of your torso at your armpits and each button on the shirt below your armpits. Write these numbers down. I use the same mantra in tailoring that I do in woodworking – measure twice, cut once.
For a nice slim shirt, I use the following calculation to find the new width across the shirt (in inches) at each point you just measured on your body: width = (circumference+5)/2. This width will give you about 1 inch of pinched fabric on each side of you. Note that for a looser fit, just change the 5 to 6.
Based on my measurements and these calculations, the width of my shirt should be 21.5″, 20.25″, 19.25″, 19.0″, 20″, and 21″ starting at the button at armpit level and working down.
Completely button your shirt, turn it inside out, and place the shirt flat on the ground or a table (not your bed, it’s too lumpy). Using your tape, and starting at the armpit, mark the new width of your shirt. I basically move the tape up the shirt until the width at the armpit seam equals the width you want
Note that altering the shirt in the manner I describe will raise the armpits. Mark this spot on both sides of the shirt. I use tailor’s chalk, or in this case a fabric marking pen, which you can pick up at Walmart for a few bucks. Once again, measure twice (notice I messed up the first time, hence the extra marks).Continue to mark the width of the shirt at each button below the armpit
Keep in mind that you can always take away more fabric, never less. So if you are unsure, start with a wider shirt; you can always go back and slim the shirt some more. Finally, the width of your shirt probably shouldn’t change by more than 1″ per button, so if you have a very ‘hourglass’ figure, you might not want to slim the shirt too much in the thinnest areas.Ultimately, I made the width of my shirt 21.5″ at the armpit, then 20.5″, 19.5″, 19.5″, 20″, and 21″ at the last button (which is where the shirt ends at the hip).
You’ll also have to slim the sleeves somewhat. Again, there’s no way around it since we are replacing the whole seam. Measure the circumference of your bicep (don’t flex) at it’s widest point. The width of your sleeve at this point will be: width=(circumference+3)/2. Again, this will give you about 1 inch of pinched fabric at your bicep; change the 3 to a 4 for a looser fit or if you’ve got really big guns when flexed. My measurement suggests that I should use a 7.5″ width, but I’m going to use an 8″ width.
Place the tape measure perpendicular to the top of the sleeve and such that it crosses the bottom of the sleeve about 2 inches from the armpit. Now measure down from the top of the sleeve to your new width and mark the sleeve at this point.
Connect these markings with those at the armpit and the seam at the end of the sleeve
At the end of the sleeve, you want the new width of the sleeve to equal the old width. Because you’ll by tying the new seam into the old seam at this point, it will look a little odd, but absolutely no one is going to notice.Here’s my shirt all marked up.
Time to start sewing. I start at the armpit to make sure the armpit seams from both sides of the shirt meet perfectly
Basically, using a straight stitch I start at the armpit and sew towards the end of the sleeve. Again, at the end of the sleeve you want the new seam to meet the edge of the shirt
Then I start at the same armpit
and sew towards the bottom of the shirt.
Do this on both sides of the shirt.Now try your shirt on
At this point, everything can be undone. If the shirt is too loose, remark it and sew it again. If the shirt is too tight, you can undo the stitching with a seam ripper. I could probably take another half inch out of each side, but I want to wear it as it is for a day before I take it in any more. Plus, I’ll be wearing an undershirt with this shirt (since it’s a little see-through), which will take up some more space.If you’re happy with the new seam, you will have to cut away the extra fabric (otherwise the shirt won’t hang quite right). However, the fabric will fray if you just cut it and leave it with normal scissors. So, you have two options: 1. you can either sew a zigzag stitch or some other stitch that prevents fraying in the fabric to be removed (i.e., between the new seam and the old seam) as close as possible to the strait stitch or I just use pinking shears to cut away the extra fabric
Pinking shears cut fabric in a zig-zag pattern to minimize fraying. I will admit that pinking shears are not an ideal way to prevent fraying, but they work well enough for me, and I’m lazy.That should be it. Here’s my newly slimmed shirt.
source : http://www.reddit.com/r/frugalmalefashion/comments/vuyb7/simple_guide_to_tailoringslimmingtaking_in_your/