Let’s be real. We’ve all been there. You grab a pair of kitchen shears, find an old Gildan promo shirt from a 5K you ran in 2018, and decide you’re going to turn it into a high-fashion muscle tank. Five minutes later, the hem is jagged, the armholes are uneven, and you’ve basically created a very expensive dust rag.
Cutting a shirt seems easy until you’re actually doing it.
The fabric pulls. The scissors snag. Suddenly, the left side is three inches shorter than the right. If you want to know how to cut a tee shirt without ruining it, you have to understand the physics of jersey knit fabric. It’s not just about the blades; it’s about tension, grain lines, and knowing that cotton shrinks and curls in very specific ways once the factory edge is gone.
The stuff you actually need (don't skip the chalk)
Most people just grab whatever scissors are in the junk drawer. That’s your first mistake. Paper scissors are dull. They chew through fabric rather than slicing it, which leads to those annoying little "teeth" marks along the edge.
You need fabric shears. They don't have to be expensive Ginghers, but they need to be sharp and reserved only for fabric. Also, find some tailor's chalk or even a piece of dry soap. You need to mark your lines. Drawing a line with a Sharpie is a gamble because the ink can bleed when you wash the shirt later.
Grab a ruler. A clear quilting ruler is best because you can see the fabric through it, but a standard school ruler works too. You're also going to want a flat surface. Not a bed. Not a carpeted floor. A kitchen table or a hardwood floor is your best bet because you need the resistance of a hard surface to keep the bottom layer of the shirt from shifting while you work.
How to cut a tee shirt for a better fit
The most common request is the "muscle tee" or the "cutoff." It sounds simple: chop the sleeves off. But if you cut exactly on the seam, the shirt will look boxy and weird.
The armhole strategy
First, lay the shirt flat. Smooth out every wrinkle. If the shirt is lumpy, your cut will be crooked. You’ve got to decide how deep you want the "drop" to be. For a standard gym vibe, you usually want to start the cut about an inch outside the collar and taper it down to about two inches below the original armpit seam.
Don't cut both sides at once.
I know, it sounds faster. But unless you have industrial-grade weights holding that fabric down, the bottom layer will slide. Cut the first side. Fold the shirt in half vertically, matching the shoulder seams perfectly. Use the first cut as a template for the second. This is the only way to ensure symmetry. Honestly, symmetry is the difference between "I made this" and "I bought this at an overpriced boutique."
The crop top transition
When you're cropping a shirt, remember the "curl factor." Most t-shirts are made of jersey knit. When you cut jersey, the edge naturally curls upward after a wash. If you want a 15-inch crop, cut it at 16 inches. That extra inch accounts for the fabric rolling and the way the shirt rides up when you move your arms.
Dealing with the neckline
The "crew neck choke" is a real thing. Some shirts just feel too tight around the throat. Cutting the neckline is high-risk, high-reward. If you go too wide, the shirt will fall off your shoulders like an 80s workout video.
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Trace the existing collar with your chalk first. If you want a raw-edge scoop neck, follow the curve of the original ribbing but stay about half an inch away from it.
Avoid cutting the back of the neck as deep as the front.
Keep the back cut high. This maintains the structural integrity of the shirt. If you cut a deep U-shape on both the front and back, the weight of the sleeves (if you kept them) will pull the shirt forward or backward all day. It’s annoying. You’ll spend the whole day tugging at your clothes.
Why the fabric type matters more than you think
Cotton is king, but 100% cotton behaves differently than a tri-blend.
- 100% Cotton: Heavy, rolls significantly at the edges, and frays very little.
- Polyester Blends: These have more "drape." They won't roll as much, but they can be slippery to cut.
- Rayon/Spandex: These are a nightmare for beginners. They stretch as you cut them, meaning your straight line will look like a mountain range once you let go.
If you’re working with a thin, stretchy blend, use pins. Pin the two layers together every two inches along your cut line. It's extra work, but it keeps the fabric from growing while the scissors move through it.
The "Pulled Edge" trick
Want that professional "raw hem" look? After you make your cut, grab the fabric on either side of the new edge and pull it tight. Give it a good snap. This forces the jersey knit to curl immediately. It hides minor imperfections in your cutting line and gives it that intentional, manufactured distressed look.
Avoiding the "pigtail" at the seams
When you're cutting across a side seam—like when cropping the bottom—the scissors often struggle with the extra thickness of the surged thread. This is where most people get a "notch" or a little "pigtail" of fabric sticking out.
To avoid this, slow down. Use the very back of the scissor blades (the part closest to the hinge) for the seams. This is where you have the most leverage and power. Once you’re through the hump of the seam, go back to using the tips for the long, smooth stretches of fabric.
Practical steps for your next DIY
- Wash it first. Seriously. If that shirt is going to shrink, you want it to happen before you cut it.
- Iron the area. A crisp, flat shirt is 100% easier to mark and cut than a wrinkled one pulled from a hamper.
- The "Safety Cut" rule. Always cut less than you think you need to. You can always chop off another inch, but you can't sew it back on without it looking like a Frankenstein experiment.
- Check your posture. Stand up. Don't cut while sitting on the floor hunched over. You need a top-down view to see if your lines are straight.
- Finish the edges? You don't actually have to sew a raw edge on a t-shirt. Jersey doesn't unravel like woven silk or denim. It just rolls. Embrace the roll.
If you’ve followed these steps, you should have a shirt that actually fits the way you envisioned. The key is patience and the right tools. Most "failed" DIY shirts are just the result of rushing. Take the extra three minutes to find a ruler and a piece of chalk. Your wardrobe will thank you.
Once the cutting is done, toss the shirt in the dryer for ten minutes. The heat and tumbling will set the curls and shake out any loose threads. You're done. Put it on and go.