How to Measure Long Sleeve Dress Shirts? | The Accurate Way

Getting the sleeve length right is the difference between a shirt that looks tailored and one that bunches at the cuff or rides up your forearm. It’s also the measurement most guys get wrong. The correct way to measure long sleeve dress shirts starts at the center back of the neck (the bone at the base of the collar) and ends at the wrist bone—but the details matter.

Sleeve Measurement: Body vs. Existing Shirt

You have two reliable paths depending on whether you’re measuring yourself or a shirt you already own. Both are accurate if you follow the right reference points.

Measuring your body takes two people to do well. Stand with your arm relaxed at your side, then slightly bend your elbow. Place the tape at the center back of your neck, run it over the top of your shoulder, and continue down the outside of your arm to just below the wrist bone.

Measuring an existing shirt is easier alone. Button the shirt and lay it flat on a firm surface, smoothing out any wrinkles. Measure from the center back of the collar down to the end of the cuff, following the sleeve’s natural curve.

The Two-Part Method Brands Use

Many shirtmakers—including Charles Tyrwhitt—split the measurement into separate segments before adding them together. This approach is more accurate because each segment follows your body’s shape.

Start at the center back of the neck, just below the collar. Run the tape to the peak of your shoulder (the bony point where the shoulder meets the arm). Note that number. Then measure from that same shoulder peak down the arm to just above the wrist bone. Add the two figures—that’s your sleeve length. Proper Cloth’s guide confirms the shoulder-to-wrist segment should end “just below your wrist,” with the elbow slightly bent.

Common Mistakes That Ruin the Fit

Most sleeve-length errors come from a handful of fixable mistakes:

• Measuring with the arm fully straight. Your sleeve needs extra length for when you extend your arm to shake hands or reach for something. A slightly bent elbow at measurement time accounts for this.
• Stopping at the middle of the hand. The cuff should sit at the wrist bone or where the hand begins to widen—not further down.
• Using the wrong shoulder reference. Some brands measure from the shoulder seam, others from the center back neck. Match your measurement method to the brand’s size chart, or you’ll be off by half an inch or more.
• Measuring a wrinkled or unbuttoned shirt. Lay it flat, button it, and smooth the fabric before you start.

Sleeve sizes are expressed in inches and typically move in half-inch increments. A quick reference for standard sizing looks like this:

These are general guides, not universal truths. A 34″ sleeve from one brand can fit differently than a 34″ from another. When you order, always cross-check your measurement against the specific brand’s chart. Charles Tyrwhitt lists sleeve sizes from 33″ to 35.5″, while Brooks Brothers pairs sleeve lengths with neck sizes (M is typically 15″-15½” neck with a 34″ sleeve). Before you invest in new shirts, check our tested picks for cotton long sleeve shirts to see real-world fits.

Match Your Method to the Brand

Each brand measures slightly differently, so consistency beats perfection. If a brand’s size guide measures from the center back neck, you measure from the center back neck. If it starts at the shoulder seam, start there.

For example, Charles Tyrwhitt’s method adds three segments: center back to shoulder peak, then shoulder peak to just above the wrist bone—and some guides include a third small segment from the collar. Proper Cloth uses the single continuous measurement from the center back neck over the shoulder to below the wrist. Either method works; what matters is using the same one the brand’s chart was built on.

When you take the measurement, keep the tape snug but not tight. A loose reading adds length you don’t need, and a tight one produces a sleeve that feels short all day.