Wi-Fi Range and RSSI Calculator

Use this tool to estimate the operating range of an indoor Wi-Fi network.

You will need to input

  • Distance from the Wireless LAN Access point or Router in meters or feet
  • Number of walls

The calculator will output the RSSI in dBm.

What does RSSI value in a Wi-Fi network mean?

RSSI stands for Received Signal Strength Indicator. The further away the device is from the Wi-Fi hotspot, the lower the value of RSSI. Here is a table that tells you what the level needs to be for good performance.

RSSI (dBm)QualityWhat does it mean?
-30 to -20Excellent No issues
-50 to -31Very good No issues
-65 to -51GoodAdequate for streaming although you might have issues with interference in apartment buildings
-90 to -66PoorMight work but will have issues with streaming and dropped connection
Less than -90Very poorThe network cannot be used

Levels in the first column will result in the performance level indicated in the second column. The impact is specified in the third column.

What is dBm?

dBm is the power in dB referenced to one milliwatt. Use this calculator to convert from dBm to Watt. It is commonly used in wireless systems.

What impacts RSSI?

Note that the RSSI value is a negative number. The access point typically puts out +20 dBm and the strength decreases exponentially with distance. Floors and walls also attenuate the signal level.

How to improve RSSI?

To improve signal levels, reduce the number of obstructions and the distance between the Wi-Fi router and any client devices.

In laptops and Wi-Fi devices like Sonos speakers, Ring, etc. the antennas are embedded within the device and the customer has no access to them. In general however, antennas have a significant impact on performance. In the case of laptops there is the option to use a USB Wi-Fi dongle with an external antenna. This will improve performance.

What is the maximum range of a Wi-Fi network?

Based on the table above, an RSSI value of lower than -90 dBm makes the network unusable. The maximum range based on the calculator is 60 meters or around 200 feet.

At distances greater than this you will not be able to connect to your Wi-Fi network. Note that if there are any walls or other obstructions the range will be reduced even further and will be less than 200 feet.

RSSI vs Distance

This table shows the values of RSSI versus distance from a Wi-Fi hotspot. We’ve picked threshold values as per the table above for the different performance levels

RSSI (dBm)PerformanceDistance (ft)Distance (m)
-30 Excellent62
-50Very good186
-65Good4012
-90Poor20060

Note that these values are calculated indoors with no walls or floors between the router and the client device (laptop for example). Walls or floors will reduce the distance further.

Wi-Fi Propagation in Free Space

Use our Antenna Range calculator to estimate the range of the Wi-Fi network in free space.

References

[1] Modeling Signal Attenuation in IEEE 802.11 Wireless LANs – Vol. 1 by Daniel B. Faria