Measure Ring Size

Guide

How to measure ring size at home

Three reliable methods, in order of accuracy. Pick the one that matches what you already have — a ring that fits, or just a strip of paper and a ruler.

Open the measurement tool

Method 1 — A ring that fits (most accurate at home)

  1. Pick the right ring

    Use a ring that fits comfortably on the exact finger you are buying for, on the same hand.

  2. Measure it on screen

    Open the screen sizer, calibrate with a bank card, then match the circle to the ring's inner edge.

  3. Or measure its diameter

    Lay the ring flat, measure straight across the inside with a ruler in millimetres, and type it into the calculator.

Method 2 — Paper strip (no ring needed)

  1. Wrap a thin strip

    Wrap a thin, non-stretchy strip of paper snugly around the base of the finger. Mark where it overlaps.

  2. Measure it flat

    Lay the strip flat against a ruler and read the length in millimetres. That length is the finger's circumference.

  3. Convert it

    Type the circumference into the calculator. Measure in the evening, with warm hands, and repeat twice.

Three steps: wrap a thin non-stretch paper strip snugly around the finger, mark the overlap, lay it flat and read its length
Paper-strip method, step by step. The written steps above are the instructions — this diagram is illustrative only, and a strip in a picture is never a measurement.

Mistakes that cause wrong sizes

  • Measuring the outside of a ring instead of the inside.
  • Using stretchy string or ribbon — it gives a longer, looser reading.
  • Measuring cold fingers, or straight after exercise.
  • Measuring a different finger, or the same finger on the other hand.
  • Ignoring a knuckle that is wider than the finger base — the ring must clear it.
Note: Between sizes, or buying a wide band? Size up: half a US size for bands 6–8 mm, a full size for bands 8 mm or more. This is common jeweller guidance, not a measurement standard.

Why you can trust this result

  • Calibration uses a standard bank card (85.6 mm wide, ISO/IEC 7810 ID-1) — a physical reference, not a guess about your screen.
  • Your measurement is calculated in your browser and is not sent to a server. There is no account, and analytics runs only if you consent to it.
  • Results are guidance, not a guarantee. For an expensive or hard-to-resize ring, confirm with a professional fitting.

Frequently asked questions

In the evening, when hands are warm and at their largest. Fingers shrink when cold and swell in heat, after exercise, or after salty food.

Related guides

We use simple cookies to see which tools people use, so we can make this site better. We never see your measurements or personal details, and there are no ads. You can say no and still use everything.