Blood Pressure Cuff Size Chart: How to Measure Your Arm

Blood pressure cuff size chart

This chart is from the American Medical Association's cuff selection guide, based on the American Heart Association's 2019 measurement statement:

• Small adult cuff: arm 22–26 cm (8.7–10.2 in)
• Adult cuff: arm 27–34 cm (10.6–13.4 in)
• Large adult cuff: arm 35–44 cm (13.8–17.3 in)
• Extra-large adult cuff: arm 45–52 cm (17.7–20.5 in)

Many home monitors come with a wide-range cuff: the seven in our validated monitors guide all list 22–42 cm. Check the range printed on the cuff or in the manual against your own measurement rather than assuming the included cuff fits.

How to measure your arm

• Stand or sit with your arm relaxed at your side.
• Measure from the tip of your shoulder (the bony point at the top) to the point of your elbow.
• Halve that distance and mark the midpoint on your upper arm.
• Wrap a soft tape measure around your arm at the midpoint, snug but not tight, and read the circumference.

That number, in centimetres or inches, is what you match to the chart. If you're between sizes, ask your pharmacist or doctor which cuff they'd use. It's also worth checking which arm to use: NICE asks for both arms to be compared, as our guide to taking an accurate measurement explains.

How much the wrong cuff changes your reading

The Cuff(SZ) trial (Ishigami and colleagues, JAMA Internal Medicine 2023) measured 195 adults with a regular adult cuff and with the cuff that matched their arm. Compared with the right cuff, the regular cuff gave systolic readings that were:

• About 3.6 mmHg lower in people who needed a small cuff.
• About 4.8 mmHg higher in people who needed a large cuff.
• About 19.5 mmHg higher in people who needed an extra-large cuff.

A 19.5 mmHg difference is enough to move a reading from one stage on the blood pressure chart to another, which is why cuff size matters as much as technique. The US Million Hearts list of common errors puts a too-small cuff at 2 to 10 mmHg.

What the cuff's inner bladder should cover

The part that inflates (the bladder) is what has to fit. The AHA's 2019 statement says its length should be 75% to 100% of your arm circumference and its width 37% to 50%. The 2024 ESC guideline gives 35% to 50% for the width. You don't need to measure the bladder yourself: buying the cuff size that matches your arm on the chart takes care of it.

If standard cuffs don't fit your arm

• Try an extra-large adult cuff first; many monitor makers sell one separately.
• If your upper arm is cone-shaped (wider at the top), the AHA statement suggests a cone-shaped (tapered) cuff.
• If an extra-large cuff still doesn't fit, the AHA statement says blood pressure may be measured at the wrist, with the wrist held at heart level. The AMA's cuff guide also says wrist cuffs are for when an upper-arm cuff can't be used, for example because of arm size.

Bring your monitor to an appointment so your doctor or nurse can check the cuff fit and compare your monitor's reading with theirs. Our guide to wrist vs upper-arm monitors covers the wrist option in more detail.

Choosing a monitor with the right cuff

Validated device lists record the cuff sizes each monitor was tested with. STRIDE BP, for example, shows validated cuff sizes in centimetres for each listed model. Our guide to validated home monitors, linked above, covers how to use those lists.

Whatever monitor and cuff you end up with, the CardiLog app works with it: you type the reading or photo-scan the display, so a cuff change never means switching apps.