Audio Services Division

Mass Media Bureau -- Federal Communications Commission
3rd Floor -- 1919 M Street NW -- Washington, DC 20554


FM Station Separation Standards

The following table lists the FM spacing standards contained in 47 CFR Section 73.207 of the FCC's rules for the various classes of FM Commercial Radio Stations in the USA. These standards must be met before a petition for rulemaking may be filed for a new FM allotments. FM applicants for an existing commercial allotment may in some cases apply for (on FCC Form 301) a transmitter site which is closer spaced than these requirements, provided that the conditions of 47 CFR Section 73.215 are met. In addition to these separations, applicants or petitioners for Channel 253 (98.5 MHz) must also meet the I.F. spacing with respect to TV Channel 6 stations.

Applicants and petitioners for rulemaking within 320 km of the Canadian and Mexican borders must meet different spacing standards with respect to foreign stations. These are located in the Canadian Border Zone Spacings and the Mexican Border Zone Spacings documents.

Noncommercial Educational FM stations on Channels 218, 219, and 220 must also meet these separations with respect to commercial FM stations and vacant allotments on Channels 221, 222 and 223. The I.F. separation requirements in the following table also apply to noncommercial educational stations.

Spacings should be rounded to the nearest kilometer.

Minimum Distance Separation Requirements in Kilometers


Table A, Section 73.207
Relation Co-Channel
(Same Frequency)		 200 kHz
(First-Adjacent Channel)		 400 or 600 kHz
(Second- or Third-Adjacent Channel)		 10.6 or 10.8 MHz
(I.F. Channel)
A to A 115 72 31 10
A to B1 143 96 48 12
A to B 178 113 69 15
A to C3 142 89 42 12
A to C2 166 106 55 15
A to C1 200 133 75 22
A to C 226 165 95 29
B1 to B1 175 114 50 14
B1 to B 211 145 71 17
B1 to C3 175 114 50 14
B1 to C2 200 134 56 17
B1 to C1 233 161 77 24
B1 to C 259 193 105 31
B to B 241 169 74 20
B to C3 211 145 71 17
B to C2 241 169 74 20
B to C1 270 195 79 27
B to C 274 217 105 35
C3 to C3 153 99 43 14
C3 to C2 177 117 56 17
C3 to C1 211 144 76 24
C3 to C 237 176 96 31
C2 to C2 190 130 58 20
C2 to C1 224 158 79 27
C2 to C 249 188 105 35
C1 to C1 245 177 82 34
C1 to C 270 209 105 41
C to C 290 241 105 48

Spacings to Canadian Stations, Spacings to Mexican Stations, Channel 253 - TV Channel 6 I.F. Spacings