In this article we calculate the distance covered by a 1000 Watt FM Transmitter.
FM transmitters are used in many different broadcast applications. When planning a system a radio engineer needs to know how far a broadcast will reach. We created a tool to make this easy.
FM Transmitter Range Calculator
In the calculator below, enter:
- Transmitter power 1000 Watt (converts to 60 dBm)
- Receiver sensitivity (refer to the second table below with dBm values for Rural, Urban or Large City)
- Transmit Antenna Gain
- Receive Antenna Gain
Example Calculation
According to the ITU, the following table shows required sensitivity in dBuV/m for FM in various environments. We have used the dBuV/m to V/m calculator to convert the units.
| Environment | Field Strength (dBuV/m) | Field Strength (V/m) |
| Rural | 54 | 0.0005012 |
| Urban | 66 | 0.0019953 |
| Large Cities | 74 | 0.0050119 |
The field strength is used to calculate the input power at the receiver in dBm. In this case the antenna gain of 0 dBi is used. However you can substitute any value in this calculator. As well, for FM, the frequency range is 88-108 MHz, so we have used 108 MHz in the computation.
| Environment | Field Strength (V/m) | Power (dBm) |
| Rural | 0.0005012 | -64 |
| Urban | 0.0019953 | -52 |
| Large Cities | 0.0050119 | -44 |
Note that cities are more challenging RF environments, so the required power is higher relative to a rural environment. There’s a 20 dB difference between the two. These are receiver sensitivity values that can be substituted in the range calculator above.
What is the Range of a 1000 Watt FM Transmitter?
Based on the calculation above, the range for different operating environments is:
- Rural – 350 km or 218 miles
- Urban – 88 km or 55 miles
- Large City – 35 km or 22 miles
As would be expected the range is the lowest in a city where buildings and other large objects will obstruct the FM signal. This means it will not travel as far in a city as it will in a rural environment.
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