I picked up this dress shirt at Goodwill for $9. To say it fit terribly would be putting it lightly. It’s probably one of the worst fitting dress shirts I’ve ever tried on, and I’ve tried on a lot. I’m by no means a small guy, and I was drowning in this thing. But the final results? They blew even ME away! I honestly planned on using it simply for making this tutorial but…I really like it now and will probably wear it regularly!

I’m gonna show you how I slimmed the sides and added darts to this bad boy. You can replicate these steps on literally any baggy dress shirt you own.

Tailoring a dress shirt on your own might seem overwhelming, especially if you’ve never used a sewing machine. I totally get it. They can do a lot of different things. But if you just wanna make your clothes fit better then they’re surprisingly easy to handle, even with zero experience. Let’s go.

The Setup: Preparing for the DIY Magic

• Sewing machine

• Clothes pins

• fabric measuring tape

• ruler (optional)

• fabric marker/chalk

• sewing pins

• iron

• 30 minutes of your afternoon

Turn your dress shirt inside out and button it up while wearing it. This might sound a bit weird but we’re sewing the inside anyway. Save yourself some time by putting the measurements on the inside instead of repeating the process later.

You Gotta Pin It to Win It

Grab eight clothespins; we’re going on a little pinning adventure placing 4 of them on each side. Start at the bottom of your shirt and pinch and place the first pin about half an inch to an inch inward on each side (12-25 mm). This initial pinning helps you get a good idea of how much fabric you’ll need to take in for that fit you’re looking for.

As you move up the shirt, place pins strategically above the hips and mid-torso. See how each pin feels—should it be tighter or looser? Adjust accordingly if you need to. This is your dress shirt so you’re in charge. This process isn’t just about following steps; it’s about seeing and more importantly FEELING how the shirt fits. Also, take off less than you think you might want too since we’re adding darts to the back as well. If we take off the “right” amount from the sides then adding darts will end up making it too tight in the end.

Sleeve Adjustments: Be Careful…

If your sleeves feel like gigantic wizard robes you can slim those as well. On this shirt I don’t need to but let’s assume you do. When you put clothes pins in the sleeves you want to be very careful not to make them too tight. Perform what I call the 'flex test'—bend your arm and make adjustments with clothespins to make sure you still have good mobility. You want the sleeves snug but not restrictive in any way—you don’t want to split your sleeve while reaching up to grab something. Oddly specific I know…

Don’t Panic!

Your clothes pins are gonna look kinda weird with your dress shirt just all bunched inside of them. Don’t freak out and think “what is this idiot guy having me do?!” These are just here to give us a rough estimate on how much we want to take off of our shirt. They aren’t permanent spots by any means.

I mean even looking at the pictures its like “uhhh…wait what?”

Marky Mark Time!

Mark those spots where your clothes pins are with a fabric marker or whatever it is that you’re using to mark. These marks are essential; they are our rough guide to how much we want to slim our shirt by, plus it means we can remove our clothes pins. Your marks don’t have to be super dark either. You just want them to be visible when you’re looking for them. Plus if they’re too dark they might not wash off as easily in the washing machine.

When you’re done making your marks, iron down the seams you’re working with. A flat, crisp seam is way easier to work with and makes sure your adjustments are as accurate as possible. This shirt has whats called a flat fell seam, they’re super comfortable because they lie flat on the side of your body. When it comes to tailoring it just fold it down to one side and then iron it down. Yes, you can do this in the very beginning if you want. I just happened to do it after making my marks haha!

Precision Pinning: From Marks to Pins

Now, measure from the very bottom of your shirt all the way up to the seam that runs under your armpit and note these measurements. It helps in keeping your adjustments proportional and even on both sides of the shirt. My shirt is 17 inches or 43 cm in length. Your measurements will vary depending on the size of your shirt. Now, I suggest put 4 sewing pins starting at 2 inches or 5 cm. The next pins will be at 6 inches (15 cm), 10 inches (25 cm), 14 inches (35 cm), and finally 17 inches (43 cm). obviously our clothes pin marks won’t be at these exact marks, so move them as close as you can to each one. That way this method is repeatable on other dress shirts of a similar size.

Since your dress shirt probably won’t be exactly 17 inches like mine, do your best to get that last pin on the body about an inch away from the armpit seam. Also, if you’re continuing on through the sleeve to slim those as well, then place that first sewing pin on your sleeve about an inch down as well. When you’re connecting those two points when sewing, you want to make a 50 degree angle between them. I’ve found that gives me a good fit under my arm without any chaffing or anything like that. It allows my dress shirt to sit nice and flat. If you’re going all the way down and tapering the sleeves too you want to put a sewing pin about 2 inches or 5 cm from the bottom of the cuff. Once you get to that point you want to have ended your taper and be sewing more so straight. That will leave you with the ability to still roll your sleeves up and not make them too tight.

Ask me how I know…

Transfer your marker dots into sewing pin placements. Start at the bottom with a sewing pin at every significant adjustment point you marked. Again, move it as close to the specified measurements as possible. Although how much I’m removing from the sides will be different from yours I’ll show you what I’m taking off anyway. It’s actually REALLY insane, at one point I’m removing 2 and 3 inches from the middle! That’s SUPER aggressive! Like…that’s borderline almost too much to remove from a dress shirt. I usually remove between 1 to 2 inches max. Now the funny thing is that STILL wasn’t enough…but we’ll get to that in a minute.

My Little Pinning Hack (Optional)

This part is optional, but when I put sewing pins in my dress shirt I like to put my pins on opposite sides of my dress shirt. The reasoning behind that is if I pin normally, then I will have a solid clean pass through my sewing machine on one side where the bulk of my garment is off to the side of my machine. Great right? Well yeah it is, but that means the other pass will be harder because I will have the bulk of my garment between my machine and needle. That means I’ll have to kind of stuff it underneath there to the other side. It sucks doing that, so if you pin opposite sides you can take advantage of a clean sewing machine pass TWICE!

Try That Mofo On (Again)!

Once you’ve got everything pinned up try on your dress shirt to see how you like the fit. Remember, you wanna make sure it looks good and FEELS good as well. If any of the pins feel too tight or too loose then just adjust them a bit and see if it feels better. It can seem tedious, but again this method is repeatable so if you get the same size shirt you don’t have to do this again. My shirt was still pretty loose, at least too loose for my liking. You want to leave room for your darts…but, well you’ll see.

Let’s Sew Bro!

Any used $50 sewing machine will get the job done for you. You DON’T need an expensive fancy sewing machine for this at all! You can find one on eBay or Facebook Marketplace that will knock it out of the park for projects like this. Use the settings below on your sewing machine for stitching up the side seams. We’ll also be using a universal needle 80/12 as well as some polyester thread. Both of which can be bought at Walmart for like $5.

Start off with a back stitch to lock in your stitch so that it doesn’t unravel on you later. Go slow and basically play connect the dots with your sewing pins. When you get to your pins make sure you don’t sew over them! That can break your machine or your needle. One time I broke my needle and felt a small sharp pain on my cheek. It was my needle tip hitting it…I shutter even just remembering that.

If you’re sewing through and tapering the sleeves then don’t forget to connect those two points at about a 50 degree angle. It doesn’t have to be EXACTLY 50 degrees so don’t sweat it if you’re off a bit, you won’t ruin your shirt or anything.

If you’re just slimming the body however then when you get to that last pin then just taper your way back out towards the outside ending your stitch just under your armpit seam. Maybe I’ll call it an underarm seam from now on, sounds more pleasant…

Finished Side Seam: Holy Smokes…

When you’re done with that straight stitch take a look at what you got. This was an INSANE taper, usually they won’t be this sudden and aggressive. But because this shirt was so big to begin with this is what we had to do.

Try it on and see what you think. Nothing is final yet so theres still time to make adjustments if you aren’t happy. This fit to me is…ok. We can do just much better than this. However like I said its important to err on the side of caution so we’ve got some room to add our darts.

If you’re happy with the new fit then you want to cut off the excess fabric leaving about a half an inch or 12 mm. This is whats called your seam allowance. It’s has a weird name that doesn’t describe what it is at all, but its just the distance between your new stitch and the edge of your garment where you cut. All of that fabric will fray on you in the washing machine so its important to finish it. We can do that in one of two ways.

One is using the zigzag stitch setting on your sewing machine. Set your stitch width to between 5-7, or as wide as your machine will allow you too. Set the stitch setting to zigzag stitch, and the stitch length is our standard 2.5. This stitch will make an overlapping pattern on the edge.

The other way is using pinking shears, which are those zigzag scissors that cut said pattern into the edge achieving the same result. Either one is fine.

Now, regardless of whether or not your happy with the fit on your side seams, if you still have a lot of excess fabric on the back then you’ll want to add some darts. This is really hard to get rid of just by taking in the sides. I like to say taking in the sides to fix the area in your lower back is like using a 2 dimensional solution to solve a 3 dimensional problem. It doesn’t work that way.

However I do wanna say that darts aren’t MANDATORY. I’ve tailored many dress shirts where all I needed to do was slim the sides a bit and I was very happy. This shirt though…yeah it needs darts REALLY bad!

Darts For A TRULY Great Fit

Darts are key for removing that baggy look from the lower back of your shirt. Like we said the side seams can’t do it on their own. To start, measure the width of your shirt’s back, decide where the darts should start, and pin them. Darts should taper as they move down, fitting the shirt closer to your lower back without making it overly tight.

And they’re way easier than you think.

Start by taking your fabric measuring tape and measure from each side of your shirt at its widest point, usually under your armpits. I’ve said armpits way too many times in this tutorial.

My shirt is 25 inches or 63 cm.

Put two sewing pins in closer to the middle of your lower back on that line you just measured. I usually I will put my pins 7 inches or 17 cm from each side, but this shirt was so massive to start that I put my pins at 8 inches or 20 cm. That way I can make sure my darts are better located on my back.

Add two more sewing pins at the bottom of your shirt directly below each of the top two pin locations. Having stripes on my shirt makes this way easier thats for sure. That being said if your lines aren’t PERFECTLY straight it’s all good!

Do you see those lines in between that the 4 pins make? Those lines are gonna be our darts. Grab each top and bottom sewing pin and pinch.

Now you want to run an iron on that line you pinched to hold it in place. Use some starch if you have some to make it stronger as well. Put one of your sewing pins through your dress shirt to help hold that ironed dart in place.

Now grab your fabric measuring tape so we can get these pins into position. Put your first pin at 1 inch or 2.5 cm from the bottom of your shirt. Not including the very top pin, you want to now add 3 more sewing pins in the middle which will each be 5 inches or 12 cm apart.

These are the measurements I usually use for my darts. Experiment with the pin placements (or try these and see if they work for you) to see whats comfortable. Now, I said usually because these measurements ended up not being good enough for this massive shirt, but we’re getting ahead of ourselves.

As you can see the very top pin is at zero. That’s because that’s the spot where our dart will be finished on our shirt. So that means by the time we get to that pin we want to have tapered completely back out towards the back of our shirt.

Put your first 3 bottom pins between .25-.5 inches or 6-12 mm to start. Depending on the size of your shirt that might be too much or too little. There will be some time to adjust later on if you need to.

You want the next pin to start your taper back out so place that one further towards the edge of your shirt at about .25 inches or 6 mm (depending on what you chose for the first 3 pins).

Remember, by the time your stitch is at that top pin you want to be completely finished with your taper. That top pin means THE END.

Try it on with the darts on it (inside out again like last time) and see how it feels. This part really catches guys off guard because they think that because their shirt is touching their lower back that it’s too tight. That’s not the case, it’s just the first time that a dress shirt has fit you properly, most likely ever. That being said, if it DOES feel too tight or restricting then adjust the pins around to different measurements to see what you like.

My shirt fits…once again ok I think I could do better. But again we’re getting ahead of ourselves. I don’t want to spoil anything.

Sewing Some Darts: Bringing It All Together

Thread your machine with a universal needle and polyester thread, and use the same settings as the previous straight stitch. Again, start with a back stitch to lock in your stitch and take your time.

Whats funny is sewing darts can seem sort of intimidating at first, but they’re actually even easier than taking in the sides. that’s because once you get everything set up between the measuring and pinning and what not, this part is a breeze. Think about it, you’re sewing as straight as possible, and then tapering out slightly at the end. That’s it.

Remember, once you’re sewing in between the second to last and last pin you want to start tapering your stitch out. Do gradually instead of aggressively to make a smoother appearing looking dart.

You want to be dancing RIIIGHT on that edge once you’re up by that last pin. The more gradually you get there the better. Sew slowly up here, your sewing machine’s pedal is pressure sensitive so there’s no need to speed through this at all. Once you’re finished back stitch ONCE MAYBE TWICE to avoid any puckering at the top of your dart. Some people suggest not back stitching at all and hand tying them instead. That’s fine if you want too but I usually don’t.

When you’re done, cut off the extra threads you will have at the top and the bottom of your stitches. No need to cut the darts off, you can just iron them down flat instead. This also gives you the ability to remove them in the future if you want too (in case you eat too many Oreo’s or something).

Iron the outside of your shirt so everything is nice and flat. Also check for any dimples at the top of your darts too. You might think it’s a bad idea to put darts in a shirt that has a pattern but it isn’t. Yes the pattern warps a bit, but having it fit your back much better is WAY better than having everything straight but super baggy.

Final(ish) Fit: The Moment of Truth

Try that mofo on again and see what you think. Is it too tight, too loose? To me my results are (surprise surprise) only ok. I knew I could do much better than this.

So I did.

I took it back off and ran it back under my sewing machine. I took off about a half an inch from each side seam as well as my darts. I just sewed my darts to meet up with my stitch at the second to last sewing pin where it originally tapered. I honestly just winged it, I didn’t even do any measuring.

The Real Finish Line: Screw Settling For Less!

What I ended up with was the fit I was REALLY looking for and one that I knew was possible! Now my dress shirt fits perfectly! Look at how well it fits my lower back now compared to how it looked before! I’m so glad I didn’t settle…

Don’t ever get discouraged through this process, if you aren’t happy with anything you can change it! Now you’ve got a perfect fitting dress shirt and the ability to make all of your other dress shirts fit great as well. Good luck not getting addicted to DIY tailoring…you think I’m kidding.

I’ll see you on the other side. SD out, deuces!