Metric reeds sold by Louët 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.