Print it at 100% (“Actual size”) on A4 or US Letter. Turn off “Fit to page”.

Printable Ring Sizer

Print at 100% / “Actual size”. Do not use “Fit to page”.
RingCatalog
STEP 1 · CHECK THE PRINTLay any bank card here.It must match this outline exactly.
Before you start1. Check the card outline or the 10 cm ruler below. If they don’t match, change the print scale to 100% and print again.2. Have a pair of scissors, a pen and tape ready.3. Measure at the end of the day, when fingers are largest.Size table and converter: ringcatalog.net/ring-size-chart
012345678910cm
Step 2 · Finger strip Cut along the dashed line, wrap it around your finger with the numbers outside, and read the size where the 0 line meets the strip. 034567891011121314
Step 3 · Or match a ring Lay a ring that fits on the circles. Your size is the one whose line sits just inside the ring's inner edge. Between two, choose the larger. US 314.2 mm · FUS 3½14.6 mm · GUS 414.9 mm · HUS 4½15.4 mm · IUS 515.8 mm · J½US 5½16.2 mm · K½US 616.5 mm · L½US 6½16.9 mm · M½US 717.3 mm · N½US 7½17.8 mm · O½US 818.3 mm · P½US 8½18.7 mm · Q½US 919.0 mm · R½US 9½19.4 mm · S½US 1019.8 mm · T½US 10½20.3 mm · U½US 1120.7 mm · V½US 11½21.1 mm · W½US 1221.5 mm · X½US 12½21.9 mm · ZUS 1322.3 mm · Z+1US 13½22.7 mm · Z+2US 1423.1 mm · Z+3
Accurate to about half a size. Confirm with a sample before a bulk order.ringcatalog.net