Louët Metric Stainless Steel ReedsMetric reeds sold by Lout are specified as dents per 10 cm. 40 10 means 40 dents in 10 cm. 1 inch = 2. 54 cm. Therefore, 10 cm = 3. 937 inches. Conversion: Take the first number in the reed size (for example: in 50 10, use 50; in 60 10, use 60). Divide this number by 3. 937. So, a 50 10 reed equals 12. 7 dents per inch. Using this in imperial calculations: If you need 12 dents per inch, you could, for example, skip a dent about every other inch.