"Some common French sizes with equivalent metric diameter and circumferences:"
"3 Fr is 1 mm (diameter) and 3.14 mm (circumference)"
"4 Fr is 1.33 mm and 4.19 mm"
"5 Fr is 1.67 mm and 5.24 mm"
"6 Fr is 2 mm and 6.28 mm"
"7 Fr is 2.33 mm and 7.33 mm"
"8 Fr is 2.67 mm and 8.34 mm"
"9 Fr is 3 mm and 9.42 mm"
"10 Fr is 3.33 mm and 10.47 mm"
"12 Fr is 4 mm and 12.57 mm"
"14 Fr is 4.67 mm and 14.66 mm"
"16 Fr is 5.33 mm and 16.76 mm"
"20 Fr is 6.66 mm and 20.94 mm"
Expected headings
"French sizing"