Free Ring Size Calculator
Measure Your Ring Size at Home

To find your ring size, wrap a thin strip of paper around your ring finger, mark where it overlaps, and measure the length in mm — that is your circumference. Divide by 3.14 to get your diameter. Then match it to the ring size chart on this page for US, UK, EU, India, or Japan sizes. Or use the free AI Ring Size Finder above — hold your hand to the camera and get your size in 5 seconds.

Use the free online ring sizer on this page — no app download needed. Three methods available: (1) AI Camera — hold your hand up and get an instant result. (2) Finger Touch Sizer — place your finger on screen. (3) MM Slider — drag to your ring's inner diameter if you already own a ring. All give results in US, UK, EU, India, and Japan formats.

The average men's ring size is US 10 (UK T, EU 62, India 22, 19.8 mm diameter, 62.1 mm circumference). Men's sizes typically range from US 8–14. If buying a surprise gift for a man, US 10 is the safest starting point. Most jewellers offer a free resize.

The easiest method: wrap a strip of paper around your ring finger, mark where it overlaps, measure in mm — that is your circumference. Divide by 3.14 to get diameter, then match to the chart above. Or use the free AI Camera tool on this page — hold your hand up and get your size in 5 seconds.

There are 3 easy ways to check ring size at home: (1) Use the free AI Ring Size Calculator on this page — hold your hand to the camera and get an instant result. (2) Use the Finger Touch Sizer — place your finger on the screen and match the outline, no tools needed. (3) Wrap a paper strip around your finger, mark the overlap, measure in mm, and match to the ring size chart above. All three methods give results in US, UK, EU, India, and Japan sizes.

Measuring the inner diameter of a ring you already own gives ~98% accuracy. Use a ruler or digital calliper across the inside of the ring in mm, then look up that diameter in the chart above. The paper strip method (measuring circumference) is next best at ~97%.

Measure in the evening. Fingers swell slightly through the day due to activity and heat. Evening measurement gives the largest size — which means the ring will always fit, even on swollen days.

Tanishq uses the standard Indian ring size system (letters A–Z, same as UK). Common women's sizes at Tanishq are L–N (US 6–7, circumference 51–54 mm). Men's sizes are typically R–T (US 9–10). Tanishq sizes are identical to Malabar Gold, Kalyan Jewellers, and ORRA — no conversion needed between Indian brands.

Indian ring sizes use letters A–Z (same as UK). The most common women's sizes are L–N (US 6–7, circumference 51–54 mm). Men's sizes are typically R–T (US 9–10, circumference 59–62 mm). Indian sizes from Tanishq, Malabar, GIVA, and ORRA are all identical — see the brand size table on this page.

GIVA uses the standard Indian/UK letter system. Use the AI calculator or paper strip method above, get your circumference in mm, then match it to the GIVA size table on this page. Most popular GIVA women's size: N (17.3 mm diameter, 54.4 mm circumference).

Indian sizes M–N (US 6.5–7, circumference 53–54 mm) are most common. For gifts without knowing the exact size, size N is the safest choice — it fits the average Indian woman's ring finger.

Yes — completely identical. Indian jewellery brands use the same A–Z letter system as UK. Size N India = Size N UK = US 7 = EU 54 = 17.3 mm diameter. You can use them interchangeably when ordering from UK brands too.

Oura Ring sizes run 6–13 (Gen 3) and 4–15 (Gen 4). They do not offer half sizes. If you are between sizes, always go UP — a loose smart ring loses sensor accuracy. Measure your index or middle finger (not ring finger) for Oura, as that is where most people wear it. Use the Oura size chart on this page.

Yes. Find your finger circumference in mm using the calculator above, then match it to the brand's size chart. For Oura: circumference 54 mm = Oura size 7. For Samsung Galaxy Ring: sizes S/M/L correspond to circumferences 49–58 mm. Both are in the brand tables on this page.

US ring sizes use numbers 3–15 with half sizes (3, 3.5, 4 … 15). The most common women's US ring size is 6 (16.5 mm diameter, 51.9 mm circumference). Men's average is US 10 (19.8 mm diameter, 62.1 mm circumference). All major American brands — Tiffany, Blue Nile, Kay, Zales, James Allen — use the same US standard.

UK ring sizes use letters A–Z (plus Z+1, Z+2 for larger sizes). Women's average UK size is L–N (US 5.75–6.75). Men's average is R–T (US 8.75–9.75). UK sizing is used by Pandora, H.Samuel, Ernest Jones, Goldsmiths, and Signet. Australian and New Zealand jewellers also use UK letter sizes.

Indian ring sizes use the same A–Z letter system as UK. The most common women's Indian ring size is N (US 7, 17.3 mm diameter, 54.4 mm circumference). All major Indian jewellers — Tanishq, Malabar Gold, Kalyan Jewellers, GIVA, ORRA, and Joyalukkas — use this identical system. Indian size N = UK size N = US size 7.

Tiffany & Co uses standard US numerical ring sizing (sizes 3–15, with half sizes). Their most popular women's size is US 6 (UK L, 16.5 mm diameter, 51.9 mm circumference). Tiffany recommends getting sized in-store for the most accurate fit, or using the AI calculator on this page and matching to the US column in the chart above. Tiffany sizing is identical to Blue Nile, Kay, and Zales — no conversion needed between US brands.

Blue Nile uses standard US ring sizing (sizes 3–15, half sizes available). For diamond engagement rings, Blue Nile advises ordering your exact measured size — not rounding up — because eternity bands and tension settings are difficult to resize. Use the AI calculator or paper strip method on this page to find your circumference in mm, then match to the US column in the chart above. Blue Nile size 6 = 16.5 mm diameter = 51.9 mm circumference.

US size 6 (16.5 mm diameter, 51.9 mm circumference, UK L, EU 52) is the #1 engagement ring size in the United States — accounting for about 20% of all sales. If buying a surprise ring, US 6 is the safest starting point. Most US jewellers — Tiffany, Kay, Zales, Blue Nile — offer one free resize within 30–60 days, so you can always adjust after.

Japanese ring sizes use numbers #1–#30. Women's average is #11–#13 (US 5.5–6.5, circumference 46–53 mm). Men's average is #20–#22 (US 10–11, circumference 62–65 mm). Major brands — Tasaki, Mikimoto, 4°C, Agete — all use the same # system. See the Japan brand size chart on this page.

Japanese #14 = US 7 = UK N = 54.4 mm circumference. A rough formula: US size ≈ Japan # ÷ 2. For exact conversions, find your Japan # in the chart above and read across to US. When between sizes, Japanese brands always recommend going up.

Mikimoto uses the standard Japanese ring size system (#1–#30). Women's most common sizes are #11–#13 (US 5.5–6.5). Mikimoto pearl rings are sold in specific sizes — if between sizes, always go up. Use the Japan size chart on this page and find your # size to order from Mikimoto.

Tasaki follows the standard Japanese # sizing system. Average women's Tasaki size is #11–#13 (US 5.5–6.5, circumference 46–53 mm). Men's average is #20–#22 (US 10–11). Tasaki, Mikimoto, and 4°C all use identical Japanese # sizes — no conversion needed between these brands.

UK ring sizes use letters A–Z (and Z+1, Z+2 for larger sizes). Women's average is L–N (US 5.75–6.75). Men's average is R–T (US 8.75–9.75). UK sizing is identical to Indian sizing — size N UK = size N India. Pandora, H.Samuel, and Signet all use this system.

UK L = US 5.75, UK N = US 6.75, UK P = US 7.75, UK R = US 8.75, UK T = US 9.75. Each letter up is approximately +½ US size. Use the complete conversion chart on this page for exact values.

Yes — Pandora uses the standard UK A–Z letter system. Pandora size N = UK size N = India size N = US 6.75 = 54.4 mm circumference. If you know your UK ring size, it works directly for Pandora without any conversion.

EU sizes equal the inner circumference in mm. US 6 = 51.9 mm ≈ EU 52. US 7 = 54.4 mm ≈ EU 54. Use the complete chart above — find your US size and read across to EU.

Measure circumference in mm, then use: US size = (circumference mm − 36.5) ÷ 2.56. Example: 54.4 mm → (54.4 − 36.5) ÷ 2.56 = 7.0 (US size 7). Or simply look up the mm in the chart above.

Always go up to the next half size. A slightly loose ring is far easier to resize than one that won't pass your knuckle. If your circumference falls exactly between two rows in the chart, choose the larger size.

Yes — cold shrinks fingers by up to 1 size; heat expands them. Avoid measuring right after outdoor cold, exercise, or a hot shower. Room temperature (20–22°C) gives the most stable measurement.

~85–90% accuracy under good lighting with your ring or middle finger held steady. For higher accuracy, use the Paper Strip method (~97–98%) — wrap a strip around your finger, measure the length in mm, and look it up in the chart above.

Diameter is the straight-line distance across the inside of the ring (in mm). Circumference is the distance around the inside — circumference = diameter × 3.14159. Both measurements are shown in the chart above.

Yes — wider bands fit tighter because they cover more of the finger. The rule: 5–6 mm bands → go up ½ size. 7–8 mm bands → go up ½ to 1 size. 9 mm or wider → go up 1 full size. Thin and standard bands (1–4 mm) need no adjustment. See the Band Width Guide on this page.

For wide wedding bands (6 mm+), order ½ to 1 full size larger than your measured ring size. 6 mm band: +½ size. 8 mm band: +½–1 size. 10 mm band: +1 full size. Eternity bands and tension settings cannot be resized — order exact for those.

Children's sizes vary by age: babies (0–12 months) wear US 0–1 (36–39 mm circumference). Children 4–6 years: US 2–3 (42–44 mm). Children 7–9 years: US 3–4 (44–47 mm). Preteens 10–12: US 4–5 (47–49 mm). Teens 13+: approach adult sizing. Always measure the child's finger — ages are approximations. See the Children's Ring Size Chart on this page.

Use the paper strip method: cut a thin strip of paper (≈5 mm wide), wrap it snugly around the base of the child's finger, mark the overlap, and measure in mm — that is the circumference. Match it to the children's chart on this page. Measure in the late afternoon when fingers are slightly warmer. For babies and toddlers, always choose a looser fit for safety.

Yes — use the free Printable Ring Sizer on this page. Set your printer zoom to exactly 100% (no "fit to page"), then print. Verify the calibration bar on the printout matches a credit card (85.6 mm wide). Hold your existing ring over the printed circles to find your size, or cut out a strip and wrap it around your finger.