Ring Size Converter
Convert ring sizes between US, UK, EU, Japanese, and inside diameter (mm). Bidirectional conversion with a full reference chart and printable ring sizer strip.
Loading Tool...
Applications
Quickly convert ring sizes between US, UK, EU, Japanese, and inside diameter (mm) systems. Perfect for international jewelry shopping, comparing sizing standards across brands, and finding the perfect ring fit whether buying online or in person. Includes a printable ring sizer strip for accurate at-home measurement.
Conversion Reference
US ring sizes (1-27+ in half-steps) are mapped to inside diameter starting at 12.4mm, with each 0.5 US step adding 0.3mm in diameter. UK sizes (A-Z+ in half-steps) follow the same underlying diameter progression with letter labels. EU sizes are based on inner circumference in millimeters. Japanese sizes follow the US numeric scale. The printable ring sizer strip uses actual circumference measurements to place tick marks at true scale for accurate paper-based sizing.
Fun Fact: Ring sizing dates back to ancient Egypt, where rings were made from reeds and hammered metal. The modern standardized ring sizing system wasn't developed until the 1920s when jewelers needed a consistent way to measure fingers across different regions.
Related Tools
View all toolsRoman to Integer
Convert Roman Numerals back to standard decimal numbers. Decipher ancient dates and numbers.
Cooking Measurement Converter
Convert between volume (cups, tbsp, tsp, ml, fl oz), weight (g, oz), and ingredient amounts for cooking and baking. Includes density table for water, milk, flour, sugar, butter, oil, and honey.
Concrete Calculator
Estimate the amount of concrete needed for slabs, footings, and columns. Calculate bags required for your construction project.
Concrete Bag Calculator
Estimate the number of pre-mixed concrete bags (60 lb or 80 lb) needed for slabs, footings, posts, and small pours. Enter dimensions, get bag count, volume in cu ft and cu yd.
Acceleration Converter
Convert acceleration units like m/s², g-force, and ft/s². Physics and automotive engineering tool.
XML to CSV Converter
Convert XML data to CSV format. Export your data for spreadsheet analysis.