Kamatsu metric conversion figures.

Grams:

6-8 grams = 1/4oz class

12-15 grams = 1/2oz class

24 grams = 3/4oz class

45 grams = 1.5oz class

Millimeters

60mm = 2.35"

75mm = 2.95"

90mm = 3.5"

100mm = 3.94"

115mm = 4.5"

130mm = 5.0"

155mm = 6.0"