Make a t-shirt fit : How to re-shape your oversized, baggy tshirts

A tutorial to transform oversized and baggy t-shirts into well-fitting one - resize and reshape t-shirts according to your measurements and preferences.

alter oversized tshirt to make it fit.

Do you know that a fitting t-shirt can take off years from your age? And weight ? Baggy t-shirts can make you look heavier – especially if the waist is not defined and the arms are not shaped. But when I got a lot of oversized t-shirts at a store for a pittance, I forgot about all these fashion philosophies.

Now I have to alter them one by one. Thankfully it is not a hard job.

Some people have different problems.

They may want a longer t-shirt – and it is difficult to find thigh-length t-shirts unless you look in the oversized section. So when you buy the t-shirt for length, it will be huge in the waist, and you will have to make the inevitable alteration to reshape it to your size.

Yet another problem occurs for those with bigger bust sizes – the t-shirt that fits across the bust will be loose at the waist and quite baggy.

The same is the case with those with broad shoulders. They may have to buy large shirts to fit their broad shoulders but, as you guessed, baggy elsewhere.

Another alteration scenario is this – I have been through this many times. I love the design so much on a T-shirt, but it is on a men’s t-shirt and way too big for me.

No worries. Wherever you are, there is a solution. The nonfitted t-shirts can be made shapely with some sewing. Use your alteration ninja techniques to change your boxy shirts to a more flattering fit.

You can reshape your t-shirt easily by taking in the sides and the sleeves and may be shaping the shoulders.

What do you need?

The 2 tshirts for the reshaping.

To complete this reshaping, you need your baggy t-shirt, a t-shirt that fits you exactly the way you want, fabric markers (chalk or the disappearing marking pen), fabric scissors, sewing pins, and a serger or a sewing machine.

If you have ball-tip needles, use that instead of regular needles. On cotton t-shirts, normal stitches and the usual needles work OK. If normal straight stitching is not working on the knit fabric, use close zig zag stitches.

What are the alterations?

Decide on what all you need to re-shape.

If it is only the sides the alteration is quite easy. But if the sleeve length and t-shirt length has to be adjusted it becomes a little more tedious. And if the shoulders are oversized, it becomes even more tedious. But nothing you can’t do.

First steps to altering your t-shirt

There are certain things you need to know before cutting into your t-shirt:

Wash your new t-shirt – if it is a new t-shirt and its fabric composition is 100% cotton, it will shrink in the wash. Even a lesser cotton- blend will shrink. So it is better to wait until it shrinks to its last before altering it. What if it shrinks to your size?

If the design on the t-shirt is on a side, it can stretch to one side when you alter it and may even disappear along the sides if the t-shirt is very large. You will have to decide if you are ready for this.

And also, if the t-shirt is too big, the neckline may be larger too and when you alter, it can look decollete.

Altering a t-shirt to fit

Find a t-shirt that fits you and is similar to the one you want to alter. 

Keep the t-shirts fitting one on top of the oversized one. Make sure that the top edges (neckline, sleeves) line up perfectly. Smoothen the wrinkles and everything.

At this point if the shoulders are droping and you want perfect shoulders, you can adjust this. For this you will have to cut off out the sleeves.

Altering the shoulders

Mark the new shoulders on the tshirt for alteration.
Mark the new shoulders on the tshirt for alteration.

To alter drooping shoulders you have to follow these steps.

Mark how much is the droop by comparing with the fitting one.

Carefully cut the sleeves off your big t-shirt with your scissors right at the seam.

Cut off the sleeves.
Cut off the sleeves at the seam line.

Cut off the extra shoulder from both the sides and then re-stitch the sleeves.

cut off the extra shoulders.
Cut off the extra drooping at the shoulders on both sides.

If you want to shorten the length of the sleeves, do this now.

Cut open the sleeves. And, cut open the sides at the seams.

Cut open the side seams.
Cut open the side seams.


Sew the sleeves back.

Keep the sleeves rightside down on the armhole line and sew them together. You are basically sewing the sleeves back to the altered shoulderline. As you sew, start from the center to the sides. Do this for both the sleeves.

Sleeves are stitched back on the t-shirt.
Keep the sleeves rightside down on the armhole line and sew them together.

Altering the length

If you are reducing the sleeves and shirt length, you can cut off the extra, add folding allowance and then fold and sew. If the whole t-shirt is long, mark the length. Remember to leave extra for folding. 3/4 inch would be enough. Cut off and then sew the new hems.

But if you are wary of sewing a new hem ( a wonky hem can ruin the whole thing) you can try folding the extra to the inside and sewing – this keeps the factory-made hem intact. But this is possible only if you have a small length to reduce.

Altering the sides

Turn the oversized t-shirt inside out.

Mark the sides for the reshaping on the baggy tshirt
Mark the sides for the reshaping on the baggy t-shirt

Keep the two t-shirts together, the fitting one on top of the oversized one, ensuring that the necklines (back neckline) are aligned together.

Also, ensure they match at the center line. Both the t-shirts should meet up perfectly at the top.

Mark around the fitting T-shirt on the old one. Using chalk or a marking pen, trace the smaller t-shirt’s outline on the bigger one. Remember you need to add extra seam allowance of 1/2 inch. (or more if you want extra ease)

Mark the sleeves straight.
Mark the sleeves straight

Pin along the mark – this prevents the slipping of the fabric. The armhole has to be aligned correctly – you have to double-check this.

Take the baggy t-shirt aside. Pin the front and the back along the mark, ensuring that the armhole is aligned.

You can baste stitch with a needle and thread if you are a beginner. Baste stitches are long hand stitches that you make before final stitching, so that you do not make mistakes. Baste stitching is done with a contrasting thread so that the thread can be removed easily.

Sew along the mark.

Clip the seam allowance at the point where armsyce and bodice meet for smooth turning. 

Sew the sides of the tshirt.

Try the t-shirt to see if it is fitting.

Sewing tips for t-shirt knits

Sewing thin knits are frustrating on an ordinary machine. Wavering hems and thread bunching up are frequent problems when sewing knits on an ordinary machine. But if you do not have a serger, what to do?

You have to be more cautious than sewing a simple woven fabric. Hold the fabric as you sew, and extra a small amount of pressure as you continue sewing. Ball tip needles are used for sewing knits because they sew through these fabrics without damaging the fibers. You can use the twin needle for coverstitch-like hems with double lines when sewing hems. If you do not have any of these, use a stretch stitch on your home sewing machine for a smoother hem. And if that is also not there, you can use a close zig-zag stitch. This stretching stitch fares better than a straight stitch with your knit fabric.

And if that is also not there, you can use a close zig-zag stitch. This is a stretching stitch and fares better than a straight stitch with your knit fabric, especially if your sewing machine has a troubled stitching past.

(If you do not have a fitting t-shirt, you can try on the big t-shirt (inside out) and then pinch the sides and pin at the sides till you get the size and fit correctly. Take off the t-shirt, and then sew along the pinned line.)

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Author: Sarina Tariq

Hi, I love sewing, fabric, fashion, embroidery, doing easy DIY projects and then writing about them. Hope you have fun learning from sewguide as much as I do. If you find any mistakes here, please point it out in the comments.

6 thoughts on “Make a t-shirt fit : How to re-shape your oversized, baggy tshirts”

  1. very nice thank you. I would love a post on how to alter ready to wear and thrift shop finds to fit a large bust. I have to get something large enough to cover the chest and then it gapes everywhere else (except my hips, because I have a small waist but very high hips. Also I am older and bust point is low. Any advice? Clothing seems to gape the most at the upper back neckline and the waist.

  2. Thanks for the information. I am ready to alter the oversized t-shirts I have to get a better fit with the additional length the t-shirt provides. So glad you wrote this article.

  3. Thankyou Sarina this is very useful as most t shirts are too wide across the shoulders for me although I have wider hips so have to buy large ones.Regards Marilyn

  4. Your website is the most comprehensive listing of home and couture sewing techniques I’ve ever found…and you’re sharing at no cost to us! Thank you so much for this amazing resource and your generosity! Really you’re amazing lol. I was wondering if you could point me in the direction of information regarding gimp tape/trim braiding possibly. You have a really good post on braiding cords, and posts about making cords, and how they’re used in sewing, but I can’t find a resource anywhere that teaches how to make specifically gimp trim. The kind they call upholstery trim, that has all the loops…I know you know what I mean. I can only find people selling it or selling the cord itself, but never a good description of the manufacturing process or any explanation of whether it requires special manufacturing equipment, therefore making it difficult to make at home. Maybe there’s some tool equivalent like a pleater for making smocking. I’m kind of at a loss here. I know how to knot hemp and cord, but not how to make those beautiful perfectly consistent loops. I’m thinking this idea of working with gimp cord could definitely be something that would fit into the idea of this site, and would definitely send people your way, since there seems to be no other resource out there for it yet.

    But yeah, you’re fantastic, and thank you for everything you’ve done here! And thanks in advance if you answer any of my questions or anything.

    P.S. Sorry if I’m leaving this comment in the wrong place or something lol.

    • Thanks for the kind and encouraging words.
      As of now, I do not know how to make them. If I find out how to, I will definitely post a tutorial.

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