If you have a shirt that’s a little too large, you can make it smaller by taking in the seams, adding darts or shortening the hems. These techniques work best for shirts that are just slightly too large, or for loose shirts that you want to make more fitted. Make sure to use thread that closely matches the shirt, especially if you want to shorten the length. This will help keep the adjustments from standing out and make the shirt look like it was made just the right size.
Decide where you want to take in the shirt. To make a men’s shirt or T-shirt smaller, you’ll want to take in just the side seams. For women’s button down shirts, you can make the shirt smaller at just the side seams, or add two extra seams (darts) to the front, back or both.
Decide how much to take in the shirt. Keep in mind that the adjusted shirt should still be at least a little bit larger than your body measurements for comfort.
Divide how much you want to take in the shirt by the number of seams you plan to adjust. (For example, to make a shirt 2 inches smaller, you could take in each side seam 1 inch or add four 1/2 inch darts.)
Turn the shirt inside out. Measure how much you want to take in the shirt from the side seams and mark this distance with pins. Stitch the shirt where you put the pins, parallel to the side seams. By making the seams larger, you’ll make the shirt itself smaller.
To add darts in the front or back of the shirt, turn the shirt inside out and make small folds in the shirt, as wide as you want the adjustments and an equal distance from the side seams. Pin these folds in place, then stitch along the pinned area. The darts can go the whole length of the shirt, or they can start just above the hemline and stop just below the bust line for a shirt that is fitted at the waist.
Press the side seams or darts so they’ll lie flat.
To shorten the hem of the shirt or the sleeves, fold the lower edge of the shirt toward the inside and pin it place, then stitch along the fold. If you need to shorten the shirt more than an inch or two, you may want to trim the bottom of the shirt and then hem it.
It’s easiest to adjust the width and length of the body of the shirt. It’s much more difficult to make the sleeve or neck openings smaller.
Use caution when working with sewing machines and irons.