How to resize a shirt that’s too small

how to resize a shirt

Resize a button up shirt. Easy sewing tutorial.

In this beginner friendly clothes upcycling video, I’ll show you one of the simple processes I use to alter shirts and tops that are too tight, increasing them by one or two sizes.

I have owned this white shirt for about 10 years. In that time, my body has changed. It’s now just a bit too small and I don’t feel comfortable wearing it. Other than that, there is nothing wrong with it. While I could donate it to a charity, a white shirt is a wardrobe staple so, rather than buy a new one, with a few simple alterations I can resize it so it has a more relaxed fit – all within about an hour or so.

Watch the video of how to resize a shirt

The design of this shirt is pretty standard. It’s got two seams at the side, a yoke at the top at the back, and a back piece. The simplest way to increase the size of this shirt is to add two panels to the side – which I call “seam extensions”.

Luckily I had an old cotton sheet in my scrap material pile that matched the fabric and colour of the shirt almost perfectly.

Step 1 – Unpick the bottom hem

Next, I unpicked and pressed out the hem at the bottom of the side seams.

Step 2 – Open up the side seams.

Then I cut the side seams from the bottom hem up to the under arm.

The inside of the side seam had been overlocked so I couldn’t simply unpick and seam rip it apart.

Step 3 – Measure and cut two side seam extension pieces

Next, I measured the length of the side seam from under the arm to the bottom hem, adding a few centimetres for a seam allowance.

Then I cut two rectangles pieces from the sheet for the seam extensions. The width of these really depends how much additional width you need to add to your particular shirt. I only wanted to add a few centimetres.

Step 4 – Pin and sew the extension pieces to the side seams

Next, I fold these in half, pressing a centre seam. I then measure down to the bottom, adding about a centimetre or half an inch all the way down so I end up with a triangle. The first piece is then the template for the second piece.

Then, to simplify the process of attaching the new side seam extensions to the garment, I press a 1cm fold similar to that of bias binding. This gives me a line to follow when I pin and sew the seam extension pieces onto the shirt.

Then it’s a matter of pinning the side seams in place.

The first piece is pinned and sewn to the outside of the garment (so, right side out). I hope this makes sense…

HELPFUL TIP: Leave a few centimetres of the seam extension piece overhanging at the top of the under arm area. This is then folded in to prevent a hole from showing at the top of the new seams.

Before sewing the new pieces in place on the machine, just double check you’ve got a new, clean seam with no puckers. Adjust your pins if you need to.

Then, sew these pieces in place. Next, turn the garment inside out and pin the other side of the seam extensions in place. Again, turn the shirt right side in and double check you don’t have any puckers. Then stitch them in place.

Step 5 – Resew the bottom hem

Once done, I press out the seams of the new pieces of fabric added and rehem the bottom. And it’s done.

The beauty of this type of alteration is that the seam extensions are obscured by your arms when you were it.

HELPFUL TIP:  I’ve done a similar alteration for a friend on a heavily patterned top. To get a fabric match for the side seam extension pieces, I was able to cut enough fabric from the bottom hem of the shirt to create the extension pieces. I’ll endeavour to do another one featuring a patterned top and upload it here.


benefits of learning to sew

The benefits of altering, mending and sewing your own clothes.

In an era of environmental consciousness, learning to sew and make your own clothes is more relevant and beneficial than ever.

Sewing skills not only mean saving money (more important in times of high cost of living) but play a significant role in reducing your environmental footprint.

Below are how learning to sew and utilising your existing sewing skills can make a positive impact on your life and the planet.

Learning to sew can be cost effective

Learning to sew and mend your clothes can lead to substantial savings now and in the long term.

Instead of discarding garments due to minor damages you can easily repair them yourself. Upcycling clothes gives them a new life, keeping then in the circular economy rather than going to landfill.

Making your own clothes means you can create custom pieces tailored to your style and fit.  Best of all, you’ll have the satisfaction of wearing something unique, knowing you made it yourself.

Sewing reduces your environmental impact

The fashion industry is one of the biggest contributors to greenhouse emissions and environmental polluters. By learning to sew, mend, and upcycle, you actively participate in reducing this impact through waste reduction, resource conservation, and by reducing your carbon footprint.

Evolve your personal style and expression

Homemade and upcycled clothes offer a unique opportunity for personal expression where you can tailor clothes to your preference, size and design.

Sewing means you can enjoy a more meaningful wardrobe that’s filled with items that you love and cherish.

Sewing enhances creativity

Sewing fosters creativity and skill development.

Upcycling encouraging you to think creatively about how to repurpose and rejuvenate old items. Sewing your own clothes allows you to experiment with different fabrics, patterns, and designs. There are no rules!

Making something with your own hands or bringing a beloved items back to life cultivates a sense resourcefulness.

Making ethical fashion choices

By making and mending your own clothes, you align with ethical fashion principles.

Fast fashion often involves exploitative labour practices and poor working conditions. By creating your own garments or repurposing second hand clothing, you know exactly where and how they were made, promoting fair labour practices and ethical production.

Sewing is less wasteful

According to the Environmental Protection Agency, millions of tons of textile waste are generated each year.

Repairing and upcycling clothes keeps them out of landfills and often being shipped overseas and burned.

By extending the life of your garments, you contribute to lowering the environmental impact of clothing waste across the world.