Metric reed conversion to inches

Metric reeds sold by Louet are described as dents in 10cm.    

• 40-10 is 40 dents in 10cm
• 1 inch -= 2.54 cm
• Therefore there are 3.937 inches in 10cm

Conversion - take the first number in the size of a metric reed (ie 50-10, use 50 - 60-10, use 60)

                   - divide this number by 3.937

Therefore a 50-10 reed is 12.7 dents per inch

To use this in imperial calculations, if you are planning 12 dents per inch, every other inch, skip a dent, for example.