Measuring the inside diameter of a ring is a quick and simple way to understand its dimensions. With just a ruler or measuring tape, you can check the internal width of the ring in millimeters or inches, and use this measurement to look up the corresponding ring size.
How to measure a ring diameter
Time:
1 minute
Tools:
Ruler or tape measure
Step 1: Lay the ruler
Lay a ruler or measuring tape on a flat, stable surface. Place the ring on top, making sure it’s level to avoid skewed readings.
Step 2: Measure the diameter
Measure the distance across the ring’s widest point, right through the center of the circle, from inner edge to inner edge.
Use a caliper for rings with raised designs or settings
Some rings, especially signet styles or those with large stones or decorative elements, can’t sit flat against a ruler or measuring tape. This makes it harder to align the edges properly. In these cases, using a caliper is the best option. It lets you measure the internal diameter directly and accurately, even if the ring’s shape or design interferes with a standard surface measurement.
Ring diameter to size standards
Use your ring’s inner diameter to find its size in any international standard. Check out our comprehensive ring size conversion chart for precise and reliable results.
View ring diameter-to-size chart
Methods that use ring’s diameter to determine its size
Ring size to diameter chart
Print a chart that aligns ring diameters with international sizing systems. It’s a reliable method to find your size quickly at home.
Diameter to size tool
Convert the inner diameter of your ring to a size using our online tool. It’s fast, easy, and supports all major international standards.
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