Bandwise

Bandwise is the calm, accurate way to find a ring size — and it works entirely on your device.

Two ways to measure:

• Match a ring — lay a ring you already own flat on the screen and size the on-screen circle to its inside edge.
• Measure a finger — wrap a paper strip around a finger and read its circumference on a true-to-scale ruler.

What makes Bandwise different:

• Accurate by design — calibrate once against any bank or ID card (a worldwide standard size) so on-screen millimetres are exact on your device.
• Truly offline — no accounts, no sign-in, no network, no tracking, no ads.
• Clean one-screen flow — your size updates live as you adjust.
• Every standard — see US, UK, EU/ISO and Japan sizes plus diameter and circumference in millimetres.

Bandwise Pro (a one-time unlock) adds the full international conversion chart, the finger ruler mode, and unlimited saved measurements for the people you shop for.

Always confirm with a jeweller before buying — Bandwise gives you a confident, well-calibrated estimate to start from.