T-Shirt Neckband Calculator
How long should your neckband be? It depends on the neckline measurement, your fabric's stretch, and the band type. This calculator does the math — including the quartering marks most patterns get wrong.
Measure the entire neckline seam on your pattern (front + back), excluding seam allowance.
Why neckbands are tricky
A neckband that's too long will stand up and gape. Too short and it puckers and feels tight. The correct length depends on how much your band fabric stretches — and most patterns assume a specific stretch that may not match your fabric.
The standard advice of “cut to 80% of the neckline” is a starting point, but it doesn't account for whether you're using self-fabric (which stretches less) or ribbing (which stretches more). This calculator adjusts the ratio based on your actual fabric stretch percentage.
Why quartering matters
Most tutorials say to “divide the band into quarters and match to the neckline quarters.” But the front neckline is longer than the back (it dips lower). If you divide equally, the front gets less stretch than the back — causing uneven tension and a neckband that doesn't lie flat.
This calculator gives you adjusted quarter marks: the front quarters are slightly longer than the back quarters. Match these to the shoulder seams and centre front/back for a perfectly even neckband.
How to measure your neckline
Stand a flexible tape measure on its edge and follow the neckline seamline (not the cutting line) around the entire front and back. If your pattern is cut on the fold, measure half the front and half the back, then double it. The number you enter should be the full circumference.