How To Upsize A Fitted Shirt – Eco Fashion Sewing

How To Upsize A Fitted Shirt

by Mariana Kirova

How to upsize a shirt - main

Lets face it. We all keep in our wardrobes some favourite garments that don’t fit us anymore. We love them so much that just can’t let them go and donate to a charity, for example.

With this tutorial you will be not just able to keep some of them longer, but also to wear and enjoy them again! 5 easy steps will show you how to upsize your favourite shirt and change it up to 3 sizes.

How to upsize a shirt - tools&materialsTools & Materials:
  • 3/4 or long sleeve fitted shirt;
  • Tape measure;
  • Seam ripper, thread snips or small scissors;
  • Corresponding colour thread;
  • Basic sewing tools;
  • Sewing machine.


Step 1: Unstitch The Sleeves

The easiest, but also the trickiest step. Be careful when unstitching the main armhole seam and the overlocking seam.

You also may prefer to just cut the sleeves around the seams. Go and do it – that’s the fastest way, for sure! Just do it carefully, close to both sides of the seam.


Step 2: Measure And Cut The Side Extensions

How to upsize a shirt easy - step 2The current upsize of fitted shirt is done by using the sleeves of the same garment. That allows to keep the clean design look with the same fabric and colour. The shirt is 95% cotton and 3% elastane woven fabric, which was really nice material to work with.

According to the standards of the garment sizing, we have to add 5cm for each size up – horizontally to each of the horizontal body lines: bust, waist and hips. Hence, if you want to upsize with 2 sizes (without adding extra room to the garment) – measure 5cm wide strip from each sleeve to add on both side seams.

So there are two things to consider here:

  • How much you want to extend the garment;
  • Do you want to add any additional room to the shirt.

If the garment has tight fit in general, as the shirt of this project, add another 1 – 1.5cm on each side (overall not more than 3cm). This way you will keep the fitted look, but also you will have a better comfortable feel when wearing after this upsize of fitted shirt.

I suggest you leave the extensions longer at the armhole. This is an easier way in which you can cut accurately and reshape the armhole later.

In terms of garment grading, enlarging a garment should be done horizontally (as it is done here), but also vertically on the garment. So, theoretically speaking, when grading one size up we also have to add 1cm vertically (from neck to hip). If you want, you can extend the length at the hem by adding a strip of garment or lace, for example.

This size chart refers to international sizing used in other countries than Australia. Sizes for fuller figure generally follow similar grading rules. However, if you are dealing with that sort of case, then try on the garment and do necessary adjustments, as human body changes differently in this size range.

Whatever the size, you only need to measure how much to extend (to add horizontally or also vertically to the length) and if there’s a need to adjust the armhole (by cutting under the armpit it to make it  bigger).

Step 3: Sew The Extensions

How-to-upsize-a-shirt-easy-step-3After checking all the measurements it is time to attach the side extensions to the garment.

You can see my shirt had additional button-up feature which I really liked and decide to incorporate in the design.

Depending on your dress shirt, your imagination and taste preferences you can work out to add something interesting too.

The sleeve may have a cuff you want to use, or it has hem embellishment – consider keeping it, it may add uniqueness to your work;).

TIP #1

TIP #2

It is a good time-saver if you use the sleeve hem. However, if you choose to cut, then consider sewing the hem before adding the extension. Will be easier because you will have both hems – of the garment and of the extension already finished.

Choose the attaching seam accordingly to the others on the shirt. In my case I attached the extension with a flat felled seam to match the overall look.


Step 4: Adjust The Armhole

How to upsize a shirt easy - step 4 - step 3Now you can shape the armhole curve and cut.

When reworking from garment with sleeves to sleeveless one, the armhole needs to be smaller (reducing circumference of the armhole) and more “open” (the armhole may need to be cut dropped).
All this is optional. I’d suggest you cut the sleeve curve and then – try on the shirt. If there’s a need, do the adjustments after.

In most cases the extra room under the arm will have to be reduced. Usually garments with sleeves have more room compared to sleeveless ones. Nevertheless, if the shirt is fitted tight on the body, might not need taking in yet lowering the hole.

If you still have to reduce the room under the arm, the easiest way is after sewing the sides extensions and cutting the curve. I did small darts under the arm on each extension.

My dart measurements are 1cm wide and 7cm long, however, yours will be different! So don’t follow this numbers, but check and measure your project. Sew the darts only when you are sure you have the correct numbers.


If you are confident in your garment construction you may decide to cut and reshape before attaching the extensions. You can either reduce from the back and front pieces of the shirt or from the extension you are going to add. However, do that only if you feel very comfortable and confident with your calculations.


Step 5: Finish With Binding The Armhole

How-to-upsize-a-shirt-easy-4For the binding you can use fabric strips from the sleeves or add different fabric. I decided not just to upsize the shirt but to change the design as well. Therefore, I’ve used another fabric for the binding.


Source your binding second hand. When in a charity shop have a look in the haberdashery section, it is always great joy to find useful bits and pieces there. Sometimes you can find ready-to-use binding attachments still in their pack and ready to use. With time you’ll gather different widths and colours, so you’ll never run out from this handy trim.


The Final Look

Upsize-fitted-shirt Refashioned-shirt-&-skirt-set

Along with the upsizing I did refashion the shirt as well. It was time to change this one colour design to something more exciting!

Even more. I combined the shirt with a skirt (which fabric I used to enhance the shirt) and created a whole new set. This article shows all the design details done on both garments.

I do hope, this upsize fitted shirt tutorial will inspire you for great sewing time! Eventually, what’s better if not bringing your faves back to life to enjoy them again?

Have good fun with such type of redo! If you feel like, share your thoughts in the comments below. I’m curious to hear your refashioning adventures.

Talk soon,










Mariana Kirova

Mariana is passionate about garment upcycling and helping others making their own upcycled clothing. Graduated with Award in garment construction from WAIFT, Perth WA, Mariana is not a main stream eco fashion designer. She makes unique eco-friendly garments from unwanted clothes and materials and believes that small fashion professionals and DIY sewers can embrace sustainability in garment creation, thus changing the fashion world for good.

  • Dori Anne says:

    Mariana, It’s a great Tute! You are off to a grand start. If you join any more social media, join Twitter. It’s a helpful venue. Many use it to link back to their blogs. I have 115,000 followers there and growing rapidly. Would be happy to retweet you if you join. It takes time to link it all together; one step at a time!

  • Thank you for the kind words, Dori Anne! I’m happy you like it.

    I know Twitter is a big platform! The number of your followers sounds great, obviously you are doing amazing work! I might jump in.

    Thanks for your comment and support;)

    Have a great day,

  • Linda says:

    Very interesting process. I can see using it in different ways. thanks.

  • Angel says:

    Do you have any suggestions on how to increase the bust in an existing top? I have an empire top that I absolutely love. It buttons in front and fits perfectly under my bust and all the way down…it flares out and fits my large hips perfectly. But my chest has grown exponentially and I can’t even button it up at the bust now. The material is velvet and it’s absolutely stunning. I can button the very top button but the next 2 buttons have about 4 inches wide open. Then button #4 fits under my bust beautifully. I was thinking to cut a slit over each breast and add material that way but have no idea if it would look awful or not. I’m afraid to just do it and risk ruining my top. I’m at a loss. Any ideas or help would be greatly appreciated. Thanks in advance.

    • Hi Angel,

      Thanks for bringing up this question. That’s often the case with time and I commend you for the desire to save your lovely top rather than throwing it away! You can definitely continue to enjoy this velvet precious. And your gut feeling is right, cutting the most obvious part could ruin it. I’m glad you listened to it.

      Here is what you can do. Instead of button up at the centre front, you can do a lace up. Check this picture from Sincerity Bridal:, it is a good visual for the case. To do the lace up you could remove the buttons, stitch up or do some small embellishments on the buttonholes, and then stitch along a lace ribbon with decorative holes, which you can use to insert the lace. Or, if possible, make more buttonholes and do the same on the opposite side of the opening. Or stitch the existing buttonholes and consider using grommets to lace it up.

      To cover the opening, behind the lace up, measure and add an insert of coordinating fabric. You can hand or machine stitch the sides to stop from moving away when you wear it. Make the insert a bit wider to give it enough room (could be folded on the sides or just gathered if it’s a thinner material). Design wise you can use lace material for that piece or anything that will complement the beauty of your top.

      And lastly, keep in mind that velvet pile can be easily spoiled from the machine presser foot or the feed dogs. Therefore, cover it with fine material/interlining while sewing, or hand stitch mainly.

      I hope that helps a bit. Let me know what you think, there’s always a solution. Great question, thanks for it.


  • >