How to Take in a Tee Shirt? | Side-Seam Slimming

Taking in a tee shirt means sewing new side seams that taper inward from the underarm to the hem, usually by 1/2 to 1 inch per side.

For the full breakdown, see our best Automotive T Shirts guide.

A baggy T-shirt hides the fit you actually want, and the fix is a straightforward sewing job. Whether you’re narrowing the torso by a half-inch or taking in a shirt that’s several sizes too big, the method stays the same: mark the new seam line, pin it, sew it, then trim and finish the edges. The entire alteration takes under an hour with a sewing machine, and even a hand-sewing version works in a pinch.

The most reliable approach is to use a shirt that already fits you well as a template. Lay the oversized shirt flat, place the good-fitting one on top, and trace its silhouette onto the larger shirt with tailor’s chalk. That gives you a precise target line to sew, including the correct sleeve and armhole shape if the shirt is dramatically oversized.

The Fastest Way To Take In a Tee Shirt

The practical route that home sewists actually use is the pin-and-sew method along the side seams. It works on any T-shirt and requires no pattern pieces.

1. Turn the shirt inside out and put it on. Pinch the side fabric at both underarms to the amount you want removed — usually 1/2 to 1 inch per side — and pin vertically at the underarm, waist, and hip.
2. Take the shirt off (still inside out) and lay it flat. Draw a smooth chalk line connecting your pins, curving gently inward at the waist if you want a tapered fit.
3. Pin along the chalk line to hold the fabric layers together, then sew a straight stitch just inside the line, from underarm to hem.
4. Trim the excess fabric to about 1/2 inch, then finish the raw edge with a zigzag stitch or serger to prevent fraying.
5. Press the new seam flat and turn the shirt right side out. Try it on — the fit should follow the line you drew.

For knit T-shirts, stretch is the one thing that matters most. A plain straight stitch will pop when you move. Use a narrow zigzag or a stretch stitch on the new seam, and finish the edge the same way so the fabric keeps its give. TextileTuts recommends moving the side seams inward by about 1/2 to 1 inch, marking at the underarm, waist, and hip for a balanced silhouette.

Preserving Stretch And Finish On Knit Fabric

T-shirt fabric is a knit, which means it stretches and recovers. The seam and its finishing must do the same, or the alteration fails the first time you bend over.

Sew the new seam with a zigzag stitch (width 2.0–3.0, length 2.0), a stretch stitch, or a straight stitch with a slight forward-backward motion on the machine. After trimming the seam allowance to 1/2 inch, finish the raw edge with a second pass of zigzag or an overlock stitch if your machine has one. Pressing matters too — press the seam allowances open before sewing the new line if the original seam is bulky, and press the final seam flat afterward. TextileTuts notes that a standard garment seam allowance is 5/8 inch, but a narrower 1/2 inch works when you’re short on fabric width.

One mistake ruins more alterations than any other: cutting before confirming the fit. Pin or baste the new seam, try the shirt on, and check that it’s not too tight across the chest or uneven at the hem. Once you cut, there’s no going back.

What About Sleeves And A Much-Too-Big Shirt?

If the shirt is only moderately baggy, side-seam adjustments alone will do the job. But when a T-shirt is several sizes too large, altering only the torso leaves mismatched shoulders and floppy sleeves that ruin the whole silhouette.

For a dramatically oversized shirt, use a well-fitting shirt as a full template. Lay the good shirt flat on top of the oversized one, align the shoulder seams and neckline, and trace the entire outline — body, sleeves, and armhole curve. Cut along your traced lines, then sew new side seams and sleeve seams to match. The armhole is the tricky part: a too-small or misaligned armhole distorts the shoulder line and makes the shirt uncomfortable. Take your time here and test the fit with pins before committing to the cut.

If the shirt is too long as well as too wide, the hem can be shortened in a way that keeps the factory bottom edge. It’s Always Autumn’s method folds the shirt up near the original hem and sews a new line just above it, so the finished bottom keeps an original, store-bought look and the stretch stays intact. The full steps cover measuring the fold, pinning it, and sewing across the width of the shirt.

Common Mistakes To Avoid

• Cutting before testing. Check the pinned fit on your body first. A too-tight or uneven seam is fixable; a cut shirt is not.
• Ignoring grain and seam alignment. If the new seam doesn’t follow the fabric’s grain, the shirt twists, ripples, and drapes unevenly when worn.
• Using a non-stretch stitch on knit fabric. The seam will pop the first time you move. A zigzag or stretch stitch is non-negotiable.
• Rushing the armhole. Misaligned armholes distort the shoulder and make the shirt uncomfortable. Sew slowly and check fit twice.

Press with a medium heat setting and test on an inside hem first — polyester blends can scorch if the iron is too hot.

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