Measuring your upper body accurately comes down to finding the right landmarks on your body, keeping your tape level, and using consistent technique each time. Whether you’re ordering clothes online, tracking fitness progress, or taking measurements for a tailor, the core measurements are the same: chest, shoulders, neck, arms, and waist. All you need is a flexible fabric measuring tape and, ideally, a mirror to confirm the tape stays level.
Chest Circumference
Your chest measurement is the most common upper body number you’ll need for sizing. Stand straight with your arms relaxed at your sides. Wrap the tape measure around your torso at the fullest part of your chest, threading it under your armpits. Keep the tape parallel to the ground all the way around, which is where a mirror helps. Don’t puff out your chest or take a deep breath. Just breathe normally and read the number while the tape sits snug against your skin without compressing it.
For women measuring bust size, the process is the same: wrap the tape at the fullest point of the bust while keeping it level. A second measurement taken just under the bust (the underbust or band measurement) is needed for bra sizing.
Shoulder Width
Shoulder width is measured between the two bony points at the outer edges of your shoulders, called the acromion processes. You can find each one by running your fingers along the top of your shoulder toward the outside until you feel a hard bony ridge where the shoulder drops off into the arm. The measurement runs horizontally between the outer edges of these two bony points.
This is easier with a helper. If you’re measuring yourself, do it from the back using a mirror. The CDC’s anthropometry protocol specifies measuring to the nearest millimeter, but for clothing or fitness purposes, the nearest quarter inch is plenty accurate. Press the tape just firmly enough to compress the soft tissue over the bone without causing discomfort.
Neck Circumference
Neck measurement is essential for dress shirts and useful as a health metric (neck circumference correlates with several metabolic markers). Stand upright, face forward, and relax your shoulders. Wrap the tape around the middle of your neck, keeping it horizontal. For men with a visible Adam’s apple, measure just below it. The tape should sit flat against the skin without digging in. You should be able to slip a finger between the tape and your neck comfortably.
Arm and Bicep Measurements
There are several arm measurements depending on your purpose, and the technique differs for each one.
Upper Arm (Bicep) Circumference
First, find the midpoint of your upper arm. Bend your elbow to 90 degrees with your palm facing up. Feel for the bony point at the top of your shoulder (the acromion process) and the bony point of your elbow. The midpoint between these two landmarks is where you’ll measure. Mark it with a pen or small piece of tape if you want precision.
For a relaxed bicep measurement, let your arm hang naturally at your side and wrap the tape around the marked midpoint, perpendicular to the length of your arm. For a flexed measurement, raise your arm to shoulder height, bend the elbow to 90 degrees, and make a fist while flexing. Wrap the tape around the peak of the muscle at that same midpoint. If you’re tracking muscle growth over time, always measure the same way (flexed or relaxed) for consistency.
Forearm Circumference
Hold your arm out with your palm facing up. Wrap the tape around the thickest part of your forearm, typically an inch or two below the elbow crease. Keep the tape perpendicular to your forearm.
Sleeve Length for Clothing
Sleeve length for shirts is not a single straight measurement down the arm. It’s two measurements added together. First, measure from the nape of your neck (the bump at the center of your spine where your neck meets your shoulders) out to the point of your shoulder where the arm starts to slope downward. Then measure from that shoulder point down the outside of your arm to your wrist bone. Add those two numbers together for your shirt sleeve length.
Bend your elbow slightly while measuring so the tape follows the natural shape of a sleeve rather than a perfectly straight arm. Your shirt cuff should land right at the break of the wrist, so measure to that point rather than past it to the hand.
Upper Waist
Though the waist is technically the border between upper and lower body, most sizing charts include it as part of your upper body measurements. Find the narrowest point of your torso, usually about an inch above your belly button. Wrap the tape horizontally around this point, keeping it parallel to the ground. Don’t suck in your stomach. Stand normally, exhale gently, and take the reading.
Tips for Consistent Results
Small technique differences can shift your numbers by an inch or more, which matters when you’re ordering clothes or tracking progress over weeks. A few habits keep your measurements reliable.
Measure against bare skin or thin, fitted clothing. A bulky shirt adds volume and makes it harder to keep the tape level. Use the same tape each time, since fabric tapes can stretch with age. Pull the tape snug so it contacts the skin around the full circumference, but not so tight that it digs in or compresses the tissue underneath. If you can see the tape pinching your skin, it’s too tight.
Take each measurement twice. If the two readings differ by more than a quarter inch, do a third and use the middle value. For fitness tracking, measure at the same time of day, since muscles can appear slightly larger after a workout due to increased blood flow. Morning measurements before exercise tend to be the most stable baseline.
A mirror positioned to your side or behind you is genuinely useful for solo measuring. The most common error is letting the tape ride up or dip down in the back where you can’t see it. If the tape isn’t level, the number will read larger than your actual circumference.
How Measurements Map to Clothing Sizes
Clothing sizes vary between brands, but your raw measurements give you a starting point. ASTM International publishes standardized body measurement tables that many manufacturers reference. For example, in women’s petite sizing, a size 4P corresponds to roughly a 34-inch bust and 38-inch shoulder girth, while a size 12P corresponds to about a 38¾-inch bust and 41-inch shoulder girth. Men’s sizing typically keys off chest circumference and neck size for shirts.
The most useful thing you can do is compare your measurements directly against a brand’s specific size chart rather than relying on the generic size number. A “medium” from one company can differ from another by two inches in the chest. Your tape measure numbers are the constant, the sizes are the variable.