Control starts with fit.

Two minutes, a strip of paper — or a ring you already own.
Find the size that disappears on your finger.

Measure it right — the 2-minute guide.

When to measure, how to wrap, and how to judge the fit like we do — 3 short steps before you commit to a size.

Find your size

Measure a ring you already own — or your finger.

Wrap a strip of paper around your finger, mark where it overlaps, and measure the length.

Recommended size
US 9 18.9 mm diameter · 59.4 mm circumference
Between sizes? Slide to compare Matches your size
Download the sizer (PDF)

Want certainty before you commit? The KiWear Sizing Kit is a full try-on set, US 5–15 — and it credits toward your ring when you order. Coming soon.

KiWear Ring — true-scale sizer

Print at 100% — turn off “fit to page”. Check the scale bar below: it should measure exactly 50 mm before you start.

Option 1 · Match a ring you own

Lay a ring that fits that finger over the circles. The circle that frames the inside edge is your size. Don’t use jewellery bands, open rings or wide statement rings — their fit isn’t equivalent.

US 5 · 15.7 mm
US 6 · 16.5 mm
US 7 · 17.3 mm
US 8 · 18.2 mm
US 9 · 18.9 mm
US 10 · 19.8 mm
US 11 · 20.5 mm
US 12 · 21.4 mm
US 13 · 22.2 mm
US 14 · 23.0 mm
US 15 · 23.8 mm

Option 2 · Wrap the strip around your finger

Cut along the strip below. Wrap it around the base of your finger — snug, not tight — starting from the 0 edge, and read the size where the strip overlaps. If your knuckle is wider than your finger base, wrap the knuckle instead and use that size.

  • Measure in the evening, 6–9pm — fingers sit at their natural daily peak. Re-check the next morning.
  • Keep your arm relaxed at your side and your hand loose; measure the exact finger you’ll wear it on.
  • Whole US sizes only. Land between two marks? Always take the larger size.
  • The right fit clears your knuckle, sits steady through your day, and leaves no mark after two hours.
Size chart

Every size, converted.

Measured in millimetres, or shopping in another system? Line up your number and read across to the KiWear US size.

Inner circ. mm Inner dia. mm US CN UK AU EU HK JP Typically fits
49.315.759JJ491010Smallest fingers, petite hands
51.816.5612LL521111Very slim fingers, teens
54.317.3714NN541212Slimmer women’s fingers
57.218.2817PP571313Universal, unisex
59.418.9919RR601414Standard men’s, fuller women’s
62.219.81022TT621515Fuller men’s, wider knuckles
64.420.51124VV651616Athletic hands, prone to swelling
67.221.41227XX671717Very large fingers, wide knuckles
69.722.21328ZZ701818Large men’s, fuller hands
72.323.01429Z+1Z+1721919Extra-large, athletic hands
74.823.81530Z+2Z+2752020Largest hands, broad palms

Whole US sizes only — no half sizes. Land between two? Always round up: a ring should breathe and keep its sensors on your skin, never pinch.
Sizing guide

Measure it right.

Two minutes of care here buys years of a ring you never notice. Three steps, then you’re done.

Step 1 Pick your moment

Measure in the evening, between 6 and 9pm — fingers sit at their natural daily peak, closest to how the ring will live on you. Re-check the next morning to see your range.

Skip it right after a workout, a hot shower or time in the sun, and when your hands are cold, stiff or swollen — those readings lie.

Step 2 Measure the right finger, the right way

Arm relaxed at your side, hand loose. Clenching or holding your hand up drains the blood and reads small.

Left and right hands differ — measure the exact finger you’ll wear it on. Wrap snug, not tight, at the base of the finger; if your knuckle is wider than the base, measure the knuckle and size to it.

Step 3 Judge the fit like we do

The right size slides over your knuckle without forcing, sits steady through typing, lifting and sleep, and leaves no mark after two hours of wear.

KiWear uses whole US sizes only. Land between two? Always round up — the sensors need contact, your skin needs room. A squeeze is never the right answer.

For your hands

  • Wide knuckle, slim base — size to clear the knuckle; a little play at the base is normal.
  • Active, or prone to swelling — size to your swollen peak and round up, so there’s room when hands warm up.
  • Slim fingers — measure relaxed, don’t cinch tight, or the ring will spin and slip.
  • Sweaty hands — dry off first, then pick the standard snug size so it stays put.

A finger can shift a full millimetre through the day — and that millimetre is the line between a ring that disappears and one you can’t wait to take off.
Sizing Kit

Try every size at home.

The KiWear Sizing Kit — a boxed try-on set of rings in every size
Coming soon
  • The full range, US 5–15 — a complete try-on set, so you test each size on the finger you'll actually wear it on.
  • Lock in your size — confirm the one that fits, and the kit credits toward your ring.
  • Made for the unsure — tricky fingers, or anyone who'd rather be certain than guess.

How you'll know it fits

  1. Slides over your knuckle easily — no catching, no squeezing.
  2. Sits steady through everyday wear — no wobble, no soreness, no pressure.
  3. After two hours of continuous wear: no marks, no discomfort.

The fit, settled.

How do I find my size?

Use the size finder above: measure a ring you already own or wrap a strip of paper around your finger, enter the millimetres, and it lands you on a US size. No printer needed — but if you have one, the true-scale sizer prints a wrap-around strip and ring circles at exact size.

When's the best time to measure?

Evening, 6–9pm, when your fingers sit at their natural daily peak — then re-check the next morning. Skip it right after exercise, a hot shower, or when your hands are cold or swollen. Keep your arm relaxed and hand loose, and measure the exact finger you'll wear it on.

I'm between two sizes — what do I pick?

KiWear uses whole US sizes only, so always round up. Paper and strip readings tend to run half to one size large, so trim a little. A ring should breathe and keep its sensors on your skin — favour a touch of room over a tight squeeze.

Does my finger type change the size?

A little. Wide knuckle with a slim base: size to clear the knuckle — a little play at the base is normal. Prone to swelling: size to your peak and round up. Slim fingers: measure relaxed so it won't spin and slip. Sweaty hands: dry off first, then pick a standard snug size.

What if it doesn't fit when it arrives?

The KiWear Sizing Kit — a full try-on set, US 5–15 — lets you lock your exact size before we make yours, and it credits toward your ring when you order. Because sizing happens before fulfillment, a bad fit is rare — but if the size you confirmed still isn't right when it arrives, we'll exchange it.

The campaign is coming

Be first when KiWear Ring goes live.

Join the list for the Kickstarter launch and early-bird pricing. One small gesture to start — we'll handle the rest.