{"version":1,"reviewedDate":"2026-09-30","title":"Belaroq calibrated ring-sizing and print-check method","canonicalPath":"/ring-sizer#measurement-method","printMethodPath":"/printable-ring-sizer#printing-method","scope":"A description of the Belaroq tool and printable method, with worked calculations. Examples are not physical accuracy tests or a guarantee of fit.","referenceDimensions":{"bankCardWidthMm":85.6,"bankCardHeightMm":53.98,"printCheckLineMm":50,"millimetersPerInch":25.4},"screen":{"formula":"Screen pixels per millimeter = matched card edge in CSS pixels / reference card edge in millimeters. Ring inner diameter = circle width in CSS pixels / screen pixels per millimeter.","example":{"referencePixels":428,"referenceMm":85.6,"pixelsPerMm":5,"circlePixels":86.5,"innerDiameterMm":17.3,"nearestChartRow":{"us":7,"uk":"N","eu":54,"asia":14,"diameter":17.3,"circumference":54.3,"usLabel":"7"}},"conditions":["Use a standard bank card matching the reference dimensions; align the full edge flat against the screen.","Calibrate on the same screen, browser zoom and orientation used for the measurement. Recalibrate after any change.","For ring matching, align the circle to the inside edge of a ring that fits the intended finger, not the outer metal edge.","A paper-strip measurement should sit comfortably and pass over the knuckle; stretching or pulling changes the result."]},"printing":{"formula":"Suggested print percentage = expected reference length / measured reference length × 100. Reprint and remeasure; do not apply a numerical correction to a finger measurement from an incorrectly scaled page.","example":{"expectedMm":50,"measuredMm":51,"correctionPercent":98.04},"conditions":["Use the PDF matching your paper: A4 or US Letter. Print at Actual size / 100% with Fit to page disabled.","Measure the 50 mm line and 1 inch line with a physical ruler, then check the bank-card frame in both directions.","If the reference marks do not match, change print scaling and reprint before using the circles or strip.","If horizontal and vertical scale disagree, stop using that printout and use another measurement method."]},"repeatProtocol":["Record three separate measurements for the same finger and hand, removing and repositioning the ring or strip between readings.","Record the method, raw millimeters, browser zoom or print setting, and the lowest and highest readings.","Cross-check against an independent method or a professional fitting, especially when readings map to different sizes.","Confirm the intended band width, knuckle passage and comfortable fit with Belaroq before production; do not average away conflicting readings."],"conversion":"The tool selects the nearest supported row of the shared ring-size chart. EU is rounded inner circumference in millimeters. Numerical step size and quarter-size labels are not a measurement-accuracy claim.","sizeRows":[{"us":3,"uk":"F","eu":44,"asia":4,"diameter":14.1,"circumference":44.3},{"us":3.25,"uk":"F½","eu":45,"asia":5,"diameter":14.3,"circumference":44.9},{"us":3.5,"uk":"G","eu":46,"asia":null,"diameter":14.5,"circumference":45.6},{"us":3.75,"uk":"G½","eu":46,"asia":6,"diameter":14.7,"circumference":46.2},{"us":4,"uk":"H","eu":47,"asia":7,"diameter":14.9,"circumference":46.8},{"us":4.25,"uk":"H½","eu":47,"asia":null,"diameter":15.1,"circumference":47.4},{"us":4.5,"uk":"I","eu":48,"asia":8,"diameter":15.3,"circumference":48.1},{"us":4.75,"uk":"I½","eu":49,"asia":null,"diameter":15.5,"circumference":48.7},{"us":5,"uk":"J","eu":49,"asia":9,"diameter":15.7,"circumference":49.3},{"us":5.25,"uk":"J½","eu":50,"asia":null,"diameter":15.9,"circumference":50},{"us":5.5,"uk":"K","eu":51,"asia":10,"diameter":16.1,"circumference":50.6},{"us":5.75,"uk":"K½","eu":51,"asia":null,"diameter":16.3,"circumference":51.2},{"us":6,"uk":"L","eu":52,"asia":11,"diameter":16.5,"circumference":51.8},{"us":6.25,"uk":"L½","eu":53,"asia":12,"diameter":16.7,"circumference":52.5},{"us":6.5,"uk":"M","eu":53,"asia":13,"diameter":16.9,"circumference":53.1},{"us":6.75,"uk":"M½","eu":54,"asia":null,"diameter":17.1,"circumference":53.7},{"us":7,"uk":"N","eu":54,"asia":14,"diameter":17.3,"circumference":54.3},{"us":7.25,"uk":"N½","eu":55,"asia":null,"diameter":17.5,"circumference":55},{"us":7.5,"uk":"O","eu":56,"asia":15,"diameter":17.7,"circumference":55.6},{"us":7.75,"uk":"O½","eu":56,"asia":null,"diameter":17.9,"circumference":56.2},{"us":8,"uk":"P","eu":57,"asia":16,"diameter":18.1,"circumference":56.9},{"us":8.25,"uk":"P½","eu":58,"asia":null,"diameter":18.3,"circumference":57.5},{"us":8.5,"uk":"Q","eu":58,"asia":17,"diameter":18.5,"circumference":58.1},{"us":8.75,"uk":"Q½","eu":59,"asia":null,"diameter":18.8,"circumference":59.1},{"us":9,"uk":"R","eu":60,"asia":18,"diameter":19,"circumference":59.7},{"us":9.25,"uk":"R½","eu":60,"asia":null,"diameter":19.2,"circumference":60.3},{"us":9.5,"uk":"S","eu":61,"asia":19,"diameter":19.4,"circumference":60.9},{"us":9.75,"uk":"S½","eu":62,"asia":null,"diameter":19.6,"circumference":61.6},{"us":10,"uk":"T","eu":62,"asia":20,"diameter":19.8,"circumference":62.2},{"us":10.25,"uk":"T½","eu":63,"asia":21,"diameter":20,"circumference":62.8},{"us":10.5,"uk":"U","eu":64,"asia":22,"diameter":20.2,"circumference":63.5},{"us":10.75,"uk":"U½","eu":64,"asia":null,"diameter":20.4,"circumference":64.1},{"us":11,"uk":"V","eu":65,"asia":23,"diameter":20.6,"circumference":64.7},{"us":11.25,"uk":"V½","eu":65,"asia":null,"diameter":20.8,"circumference":65.3},{"us":11.5,"uk":"W","eu":66,"asia":24,"diameter":21,"circumference":66},{"us":11.75,"uk":"W½","eu":67,"asia":null,"diameter":21.2,"circumference":66.6},{"us":12,"uk":"X","eu":67,"asia":25,"diameter":21.4,"circumference":67.2},{"us":12.25,"uk":"X½","eu":68,"asia":null,"diameter":21.6,"circumference":67.9},{"us":12.5,"uk":"Y","eu":69,"asia":26,"diameter":21.8,"circumference":68.5},{"us":12.75,"uk":"Z","eu":69,"asia":null,"diameter":22,"circumference":69.1},{"us":13,"uk":"Z½","eu":70,"asia":27,"diameter":22.2,"circumference":69.7}],"sources":[{"label":"GIA: Ring size guide and chart","href":"https://4cs.gia.edu/en-us/blog/how-to-determine-ring-size-tips-and-ring-size-chart/"},{"label":"NIST: The inch is exactly 25.4 millimeters","href":"https://emtoolbox.nist.gov/faq/faq.asp"}]}