Need a ring size calculator for cm to mm ring size or inches to ring size converter? Our free tool converts measurements like 2.75 inches ring size (≈69.85 mm, US size 10.5–11) for accurate jewelry sizing. Whether you’re measuring in cm, mm, or inches, our calculator and chart simplify the process for buying or designing rings.
Explore our ring size calculator cm and inches to ring size guide, perfect for jewelers, shoppers, and DIY enthusiasts.
Key Fact: 1 cm = 10 mm; 2.75 inches = 69.85 mm ≈ US ring size 10.5–11.
Our ring size calculator supports:
- Fast cm to mm ring size conversions for jewelry
- Accurate inches to ring size converter for US/UK/EU sizes
- Precise measurements for custom ring designs
- Shopping for rings online or in-store
- Metric and imperial conversions for global use
Related Tools: cm to mm, mm to cm, Inches to mm, Length Converter, or explore Metric vs. Imperial System.
Ring Size Calculator (cm, mm, Inches)
Ring Size (US): Enter a value to calculate
Input cm, mm, or inches (e.g., 2.75 inches ring size ≈ US 10.5–11). Use our chart below for exact sizing.
Ring Size Chart: cm, mm, Inches
Convert cm to mm ring size or inches to ring size with this chart:
| US Size | mm (Circumference) | cm (Circumference) | Inches (Circumference) | Example |
|---|---|---|---|---|
| 3 | 44.2 | 4.42 | 1.74 | Small ring finger |
| 5 | 49.3 | 4.93 | 1.94 | Women’s average ring finger |
| 7 | 54.4 | 5.44 | 2.14 | Men’s average ring finger |
| 9 | 59.5 | 5.95 | 2.34 | Large ring finger |
| 10.5 | 63.4 | 6.34 | 2.50 | Thumb ring |
| 11 | 64.6 | 6.46 | 2.54 | Large thumb ring |
| 13 | 69.7 | 6.97 | 2.75 | 2.75 inches ring size (e.g., oversized ring) |
Note: Measure finger circumference; 2.75 inches ≈ 69.85 mm ≈ US size 10.5–11. Try cm to mm or inches to mm for more conversions.
How to Measure Ring Size (cm to mm or Inches)
Step-by-Step Guide
Measure finger circumference
Wrap a string around the finger, mark it, and measure in mm or inches (e.g., 2.75 inches).
Convert to mm
Inches × 25.4 = mm (e.g., 2.75 × 25.4 = 69.85 mm); cm × 10 = mm (e.g., 6.985 cm = 69.85 mm).
Find ring size
Match mm to the chart (e.g., 69.85 mm ≈ US size 10.5–11).
Tip: Measure in mm for precision. Learn more at How to Convert Units.
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