The following is a chart on waveguide dimensions.

Waveguide frequency bands and interior sizes
Frequency Band	Waveguide Standard	Frequency Limits (GHz)	Inside Dimensions (inches)
	WR-2300	0.32 – 0.49	23.000 x 11.500
	WR-2100	0.35 – 0.53	21.000 x 10.500
	WR-1800	0.43 – 0.62	18.000 x 9.000
	WR-1500	0.49 – 0.74	15.000 x 7.500
	WR-1150	0.64 – 0.96	11.500 x 5.750
	WR-1000	0.75 – 1.1	9.975 x 4.875
	WR-770	0.96 – 1.5	7.700 x 3.385
	WR-650	1.12 to 1.70	6.500 x 3.250
R band	WR-430	1.70 to 2.60	4.300 x 2.150
D band	WR-340	2.20 to 3.30	3.400 x 1.700
S band	WR-284	2.60 to 3.95	2.840 x 1.340
E band	WR-229	3.30 to 4.90	2.290 x 1.150
G band	WR-187	3.95 to 5.85	1.872 x 0.872
F band	WR-159	4.90 to 7.05	1.590 x 0.795
C band	WR-137	5.85 to 8.20	1.372 x 0.622
H band	WR-112	7.05 to 10.00	1.122 x 0.497
X band	WR-90	8.2 to 12.4	0.900 x 0.400
Ku band	WR-62	12.4 to 18.0	0.622 x 0.311
K band	WR-51	15.0 to 22.0	0.510 x 0.255
K band	WR-42	18.0 to 26.5	0.420 x 0.170
Ka band	WR-28	26.5 to 40.0	0.280 x 0.140
Q band	WR-22	33 to 50	0.224 x 0.112
U band	WR-19	40 to 60	0.188 x 0.094
V band	WR-15	50 to 75	0.148 x 0.074
E band	WR-12	60 to 90	0.122 x 0.061
W band	WR-10	75 to 110	0.100 x 0.050
F band	WR-8	90 to 140	0.080 x 0.040
D band	WR-6	110 to 170	0.0650 x 0.0325
G band	WR-5	140 to 220	0.0510 x 0.0255
	WR-4	170 to 260	0.0430 x 0.0215
	WR-3	220 to 325	0.0340 x 0.0170
Y-band	WR-2	325 to 500	0.0200 x 0.0100
	WR-1.5	500 to 750	0.0150 x 0.0075
	WR-1	750 to 1100	0.0100 x 0.0050