Buying a ring online means trusting a number you measured yourself. This page exists so the number is right the first time. Three measurement methods, an international size conversion table, and a printable strip you can wrap around your finger — all calibrated for at-home use without ordering a metal sizer kit.
Method 1 — The string method (no printer needed)
- Wrap a soft string, dental floss, or a thin strip of paper around the base of the finger you'll wear the ring on. Pull it snug but not tight.
- Mark where the string overlaps with a pen.
- Lay the string flat against a millimeter ruler. Measure from the start to the mark — that number is your finger circumference in millimeters.
- Look up the millimeter circumference in the conversion table below to get your US, UK, and EU sizes.
Tip: Measure three times across the day — morning, afternoon, evening. Use the largest of the three.
Method 2 — The existing-ring method (most accurate)
- Take a ring you already own that fits the target finger comfortably.
- Lay it flat on a millimeter ruler.
- Measure the inside diameter, edge to edge across the widest point.
- Look up that diameter in the conversion table below.
Why this is the best at-home method: you're measuring a known-good fit, so you skip the guesswork of how snug "snug" should be.
Method 3 — The printable strip
Print this section at 100% scale (or "Actual size" — not "Fit to page"). After printing, use a ruler to verify the calibration bar below is exactly 50 mm long. If it's not, your printer is scaling. Re-print with scaling turned off.
Calibration bar
Once calibrated, cut along the strip below, wrap it around your finger, and read the millimeter mark where the strip overlaps. Match that to your ring size.
Strip shown at 5x scale on screen. After printing at 100% scale and verifying the calibration bar above, this strip will measure 0.5–7.2 cm of finger circumference at the millimeter marks shown.
International ring size conversion table
| US | UK / Australia | EU / mm circumference | Inside diameter (mm) |
|---|---|---|---|
| 4 | H | 46.5 | 14.8 |
| 4.5 | I | 47.8 | 15.2 |
| 5 | J ½ | 49.0 | 15.6 |
| 5.5 | K ½ | 50.3 | 16.0 |
| 6 | L ½ | 51.5 | 16.4 |
| 6.5 | M ½ | 52.8 | 16.8 |
| 7 | N ½ | 54.0 | 17.3 |
| 7.5 | O ½ | 55.3 | 17.7 |
| 8 | P ½ | 56.6 | 18.1 |
| 8.5 | Q ½ | 57.8 | 18.5 |
| 9 | R ½ | 59.1 | 18.9 |
| 9.5 | S ½ | 60.3 | 19.4 |
| 10 | T ½ | 61.6 | 19.8 |
| 10.5 | U ½ | 62.8 | 20.2 |
| 11 | V ½ | 64.1 | 20.6 |
| 11.5 | W ½ | 65.3 | 21.0 |
| 12 | Y | 66.6 | 21.4 |
Five things that change your ring size (most people don't know these)
- Time of day: Fingers can be 0.25–0.5 mm larger by evening than at morning. Always measure at the end of the day.
- Temperature: Cold weather shrinks finger size; heat expands it. Measure at a comfortable indoor temperature.
- Salt and water retention: A salty meal or a long flight can temporarily up-size your finger by half a size.
- Knuckle vs base: Many people have knuckles wider than the finger base. Size to the largest part the ring needs to slide over — usually the knuckle.
- Ring width: A wide-band ring (5 mm+) fits tighter than a thin band (2 mm) at the same nominal size. Size up half a size for wider bands.
What's covered if my ring doesn't fit
Stylr rings are sold under a 30-Day Satisfaction Guarantee with a No-Return-Needed Resolution. If your ring doesn't fit, email info@stylr.us with your order number and we'll work out a replacement, store credit, or refund — most cases without you having to ship the original back. See our refund policy for the full process.
Frequently asked questions
- How accurate is measuring my ring size at home?
- Measuring at home with a string-and-ruler method or a printable size chart is accurate within about half a US ring size. For a single ring on a single finger, this is usually close enough. For knuckle rings, eternity bands, or wide-band rings, a jeweler's metal ring sizer is the safer bet — those styles are sensitive to small fit differences.
- Should I size up or size down if I'm between sizes?
- Size up. Fingers swell mildly during the day, in summer, after meals, and on warmer flights. A ring that's a hair loose at 9am will be perfect by 4pm — a ring that's a hair tight will be uncomfortable by lunch.
- Why do my fingers measure differently in the morning vs evening?
- Body temperature, salt intake, hydration, and time of day all affect finger size by 0.25–0.5 mm. Measure at the end of the day at a comfortable room temperature for the most representative size.
- Are US ring sizes the same as UK or EU?
- No. The US uses a numeric scale (4 to 13 in half-size increments). The UK uses letters (G to Z+). The EU and most of Asia use millimeter circumference (44 mm to 76 mm). Use our conversion table below before ordering from international stores.
- How do I measure a ring that already fits me well?
- Place the ring flat on a millimeter ruler and measure the inside diameter (edge to edge across the center). Look up that diameter in our chart to get the corresponding ring size. This is the most accurate at-home method.
- What if my ring fits one finger but I want it on a different one?
- Index, middle, and ring fingers on the dominant hand are typically half a size larger than the same fingers on the non-dominant hand. Pinky fingers vary the most between people — measure each pinky individually.
- Can I resize a Stylr ring?
- Stylr rings are made from solid 316L stainless steel, which is harder than gold or silver and not field-resizable by most local jewelers. If your ring doesn't fit, please contact us within 30 days at info@stylr.us — we'll work out a resolution under our 30-Day Satisfaction Guarantee rather than recommending you take a hammer to the ring.