American (WR) and International (WG) Waveguide Sizes

WR Designation WG Equivalent Standard Freq Range GHz Inside dimensions (inches)
WR340 WG9A 2.20 - 3.30 3.400 x 1.700
WR284 WG10 2.60 - 3.95 2.840 x 1.340
WR229 WG11A 3.30 - 4.90 2.290 x 1.150
WR187 WG12 3.95 - 5.85 1.872 x 0.872
WR159 WG13 4.90 - 7.05 1.590 x 0.795
WR137 WG14 5.85 - 8.20 1.372 x 0.622
WR112 WG15 7.05 - 10.00 1.122 x 0.497
WR90 WG16 8.2 - 12.4 0.900 x 0.400
WR75 WG17 10.0 - 15.0 0.750 x 0.375
WR62 WG18 12.4 - 18.0 0.622 x 0.311
WR51 WG19 15.0 - 22.0 0.510 x 0.255
WR42 WG20 18.0 - 26.5 0.420 x 0.170
WR28 WG22 26.5 - 40.0 0.280 x 0.140
WR22 WG23 33 - 50 0.224 x 0.112
WR19 WG24 40 - 60 0.188 x 0.094
WR15 WG25 50 - 75 0.148 x 0.074
WR12 WG26 60 - 90 0.122 x 0.061