How accurate is an online on-screen ring sizer?
When calibrated against a standard bank or credit card (ISO/IEC 7810 ID-1, exactly 85.60 × 53.98 mm), ActualRingSize locks your display’s exact pixel density (PPI) down to ±0.05 mm steps—finer than quarter-size US increments (0.20 mm). For best accuracy, match the inner edge of the ring with your eye directly above the centre crosshair.
How do I measure my ring size without an existing ring?
Switch to the "Paper / string" tab or "Only my finger" optical calliper. Wrap a non-stretchy strip of paper snugly around the base of your finger, mark where it overlaps, and measure the length in millimetres against our calibrated on-screen ruler. If your knuckle is prominent, measure both your finger base and knuckle and choose the midpoint.
Should I size up for a wide wedding band (6 mm or 8 mm)?
Yes. Wide bands (5 mm to 12 mm) cover more surface area on the finger and displace more skin than a 2 mm engagement ring. Jewellers recommend going up 0.25 US size for 5–6.5 mm bands and 0.50 US size for 7–10 mm flat bands. Our control dock automatically computes this effective diameter adjustment.
What is the average ring size for women and men?
The most common women’s ring sizes are US 6 to US 7 (16.51 mm to 17.35 mm inside diameter, EU 52 to 54, UK L½ to N½). The most common men’s ring sizes are US 9 to US 10.5 (18.89 mm to 20.17 mm inside diameter, EU 59 to 63, UK R½ to U½).
How do US, UK, EU, Japanese, and Indian ring sizes compare?
US and Canadian sizes use a numerical scale (e.g. US 7 = 17.35 mm inside diameter). UK and Australian sizes use letters (A to Z) based on 0.40 mm diameter increments. EU/ISO, French, and Cartier sizes use inner circumference in millimetres (e.g. EU 54 = 54.4 mm circumference). Japanese, Chinese, and Indian sizes use distinct numerical scales mapped in our live converter.
Does ActualRingSize upload my camera feed, photos, or card details?
Never. Every calculation, credit-card scale calibration, camera overlay, and saved measurement runs 100% locally in your browser. Zero images, personal measurements, or card numbers ever leave your device.
