The free t shirt size chart calculator from Kahana Designs, a Native Hawaiian–owned studio in Kailua-Kona, Hawaiʻi, turns your height, weight, build, and fit preference into an instant unisex tee size recommendation — no guessing, no returns.
What is the T-Shirt Size Calculator?
It's a free interactive tool that estimates your best unisex t-shirt size using your height, weight, body build, and how loose or fitted you like your shirts. Instead of eyeballing a generic size chart, it calculates a body-mass-based estimate, adjusts for build and fit, and highlights the matching row on a real Gildan 5000 chest-and-length chart — the same shirt blank Kahana Designs prints its Hawaiian tees on.
How do I use the t shirt size chart calculator?
- Open the T-Shirt Size Calculator.
- Choose Imperial (lb/in) or Metric (kg/cm) units.
- Enter your height and weight.
- Select your body build — slim, average, broad, or full.
- Select your preferred fit — fitted, regular, or relaxed.
- Tap "Find my size" to see your recommended size and the full chest/length chart with your size highlighted.
Is the calculator based on real sizing data?
Yes. The chart behind the calculator matches the Gildan 5000 unisex tee — a classic, slightly boxy fit that runs true to size. If you're between sizes, sizing up gives a more relaxed drape while sizing down gives a closer, fitted look. Because 100% cotton can shrink slightly in a hot dryer, sizing up is the safer bet if you machine dry your shirts.
Every Kahana Designs tee carries a story from the islands, so getting the fit right matters as much as the design. Explore the full Hawaiian Tees collection to see the designs these size charts are built for.
Why does fit matter for Hawaiian-inspired tees?
Hawaiian aloha shirts and tees have always been meant to move — for beach days, backyard graduations, and everyday wear across the islands. A shirt cut too tight loses that relaxed, breathable feel; one sized too large loses the shape of the design across the chest. Kahana Designs prints on unisex Gildan 5000 blanks precisely because they hold up to island life while keeping a fit true enough to size confidently from a chart.
Bring the islands home: Explore our Hawaiian Tees collection — original designs from our Native Hawaiian–owned studio in Kailua-Kona, Hawaiʻi. A few of the newest additions:
Hawaii Ohana Family Tee — a family-first aloha design for matching island trips.
Hawaii Legend Status Tee — island-pride graphic for kamaʻāina and longtime visitors alike.
Aloha Social Butterfly Tee — an easygoing aloha-spirit print for warm-weather wear.
Keep reading from the Kahana Designs journal
- Hawaii T-Shirts: The Complete Guide to Authentic Hawaiian Tees
- Aloha Friday and the Rise of the Hawaiian Aloha Shirt
- What Makes Hawaiian Clothing Authentic? Aloha Wear, Culture & Design Explained
Frequently asked questions
How do I know my t-shirt size?
Measure your chest at its fullest point and compare it to a size chart, then check shirt length against a tee you already own and like. Our t shirt size chart calculator estimates your size from height, weight, build, and fit preference, then points you to the matching row so you can confirm.
Are unisex t-shirts true to size?
Unisex tees like the Gildan 5000 generally run true to size with a classic, slightly boxy fit. Those who prefer a closer cut often size down one, while anyone wanting a relaxed, oversized look should size up. The calculator adjusts for your fit preference automatically.
Should I size up or down if I'm between sizes?
Size up for comfort and a relaxed drape, or size down for a fitted look. Remember that 100% cotton tees can shrink slightly in a hot dryer, so sizing up is the safer choice if you machine dry.
Is the t shirt size chart calculator free?
Yes. The T-Shirt Size Calculator is completely free to use, with no account or purchase required.