100% Grátis • Sem Instalar Aplicativo

Descubra o tamanho perfeito do seu anel.

O medidor de anéis online mais preciso. Calibre com cartão, moeda ou régua e encontre seu aro para Brasil, Portugal, EUA e Europa.

100% no Navegador
Auto-Detect • Cartão Padrão • Moeda
15+ Countries
100% Grátis • Sem Instalar Aplicativo

Passo 1: Calibre sua Tela

Alinhe um cartão bancário, moeda ou régua na moldura para definir a escala 1:1 real.

Tabela de Conversão de Anéis

Compare o aro brasileiro com padrões dos EUA, Reino Unido e Europa.

Essential Measurement Anatomy

Inside Diameter vs. Inside Circumference

Understanding the difference is critical to avoid sizing errors. All international ring size charts are built on these two core measurements.

1Straight Measurement
d (mm)

Inside Diameter

The straight-line distance across the widest point inside the ring opening.

DIAMETER (d)
How to measure: Measure from the inside edge across the widest center to the opposite inside edge.
Best for: Measuring an existing ring that already fits you perfectly.
Never measure the outer rim: Ring thickness adds 2–4 mm, causing an error of 3 to 5 whole sizes!
2Perimeter Measurement
C = π × d (mm)

Inside Circumference

The complete continuous distance around the inside inner wall of the ring.

CIRCUMFERENCE (C)
How to measure: Wrap string or paper strip snugly around your finger base, mark the overlap, and measure length.
ISO Standard: European (EU) sizes correspond 1:1 with inside circumference in mm (e.g. 54 mm = EU 54).
Direct Finger Fit: Inside circumference exactly mirrors the perimeter of your finger tissue for 100% true comfort.
π

The Exact Mathematical Relationship

Circumference = Diameter × 3.14159 • (or Diameter = Circumference ÷ π)

Example: 17.3 mm (d) × π = 54.4 mm (C) = US Size 7
ISO / UEDiâmetro (mm)US / CAUK / AUÍndiaJapão
4915.7 mm5J99
5216.5 mm6L1212
5417.3 mm7N1414
5718.1 mm8P1716
5918.9 mm9R1918
6219.8 mm10T2220
6520.6 mm11V2423
6721.4 mm12X2625
Frequently Asked Questions

Perguntas Frequentes

Dicas de joalheiros para acertar na medida do anel sem erros.

Need more ring sizing help?

Explore our interactive tools, calculators, and printable size guides anytime.