The standard measurement, step by step
- Stand if you comfortably can (sit with the leg extended if not), weight even, leg relaxed.
- Find the kneecap center and mark three points: the kneecap center, 6 inches (15 cm) above it on the thigh, and 6 inches below it on the calf. Some products use different offsets; always follow the chart for your specific model.
- Measure circumference at all three points with a soft tape: snug against skin, never compressing. Thin clothing adds error; bare skin is best.
- Write all three down. Sleeves usually size off the knee-center or thigh measurement; hinged braces often use thigh and calf; immobilizers size by length, so also measure mid-thigh to mid-calf if that is your category.
The judgment calls
Between sizes: for compression products, size down if you want maximum swelling control and can tolerate snug; size up for all-day comfort and easier donning, especially with arthritis hands. For hinged braces, follow the larger measurement and rely on straps for fine tuning.
The swelling rule: a freshly injured, swollen knee will shrink over weeks. Measure the knee as it is today, and expect to re-tighten straps as swelling falls. If you are buying mid-recovery for the long haul, measure the healthy knee as a reference too and tell the fitter both numbers.
Left, right, and universal: some designs are side-specific (buttresses and certain hinges), others universal. Check before ordering; a left buttress on a right knee actively works against you.
The ten-minute wear test
- Walk for ten minutes. The brace stays put without a single hitch-up.
- No pinch behind the knee when you bend to sit.
- Two fingers fit under the top edge with effort; no tingling or color change below.
- Hinges (if any) sit level with the top of the kneecap, centered on the joint line.
Fail any item and adjust or exchange. Under our fit guarantee, exchanges are free for 30 days, because a brace that fails the wear test will not get worn.
Frequently asked questions
My thigh and calf measurements point to different sizes. Which wins?
For most hinged braces, follow the thigh and tune the calf with straps. For sleeves, follow the chart's primary measurement point for that product. Mismatched proportions are common, muscular calves especially, and are exactly the case where a quick call to a fitter saves an exchange.
Should I measure in the morning or evening?
If your knee swells through the day, measure in the late afternoon, the knee's larger state, so the brace never becomes a tourniquet by evening. Stable knees can measure anytime.
The brace fits but slides down. What is wrong?
Usually one of three things: top strap not anchored above the calf muscle's widest point, a size too large at the thigh, or fabric worn loose with age. Re-don it properly (seated, knee at 30 to 45 degrees for most sleeves), snug top-down, and if it still migrates, the size or model is wrong for your leg shape, which we fix free within 30 days.