How do I choose T-shirt sleeve length and width?

Short answer: Sleeve length and width are part of the overall fit. A regular tee usually has a sleeve ending around mid-upper arm with moderate width; a fitted tee has a shorter, narrower sleeve that hugs the arm; a boxy or oversized tee has a dropped shoulder and a wider, often longer sleeve. Because shoulder position changes where the sleeve starts, sleeve length should be judged together with shoulder width. Define the bicep width, sleeve opening and sleeve length on a reference size, check them on testers with different arm sizes, and grade them sensibly so sizes keep the same proportion. If your customers vary a lot, a separate fitted or relaxed style may work better than trying to make one sleeve suit everyone.

Measuring points

• Sleeve length from shoulder point or from centre back neck.
• Bicep width measured a set distance below the armhole.
• Sleeve opening width.
• Armhole depth.

Options

• Regular: moderate length and width.
• Fitted: shorter and narrower, often with stretch fabric.
• Boxy: dropped shoulder, wider and longer sleeve.
• Longline: often slimmer and longer.

Testing

Fit samples on testers with slim and muscular arms. Check comfort when lifting arms and whether the sleeve rides up. Use body measurement data, such as from ISO 8559, to understand arm girth ranges.

A worked example

The brand compares its sleeve with competitors and finds its bicep is wider and the sleeve longer. It reduces the sleeve length slightly and keeps bicep width for comfort, then launches a separate fitted tee with a narrower sleeve for slimmer customers.

Sleeve details that change the look

• Hem depth and stitch at the sleeve opening, which affect how the sleeve sits.
• Rolled or cuffed sleeves for a workwear look.
• Set-in versus dropped shoulder, which moves the sleeve start point.
• Fabric weight, since heavy jersey holds a wider sleeve away from the arm while light jersey falls closer.

Agree these details on the reference sample, as a small change can alter fit feedback as much as length does.

Grading sleeves

Grade sleeve length in small steps and bicep width in line with chest grading, so a large does not end up with a disproportionately tight arm.

Limits

Sleeve preferences vary by market and trend. Customer feedback is the best guide.

Facts, recommendations and uncertainty

Established: sleeve length and width are judged together with shoulder position. Recommendation: define key points on a reference size and test on varied testers. Uncertain: which proportion your customers prefer.

Sources and further reading

• ISO 8559-1:2017 — Size designation of clothes: anthropometric definitions for body measurement

Standards and regulations are referenced by their published scope. Test parameters, cycles and pass levels should be agreed with your laboratory for the specific product; legal requirements should be confirmed for each destination market.