RSSI to Distance Calculator
Estimate the distance between a BLE transmitter and receiver using RSSI, TX power, and the log-distance path loss model.
d = 10 ^ ((TxPower - RSSI) / (10 × n))d = 10 ^ ((-59 - (-65)) / (10 × 2)) = 2.00 mHow to Use
Adjust the RSSI slider or type a value to set the received signal strength. Choose a TX power preset matching your beacon hardware, or enter a custom value. Select an environment preset for the path loss exponent, or fine-tune it manually.
The estimated distance updates instantly as you change any parameter. Results are shown in both meters and feet.
How Does RSSI Relate to Distance?
RSSI (Received Signal Strength Indicator) measures the power of a received radio signal in dBm. The log-distance path loss model relates RSSI to distance using the formula:
d = 10 ^ ((TxPower - RSSI) / (10 × n))
Where TxPower is the expected RSSI at 1 meter, and n is the path loss exponent that models the environment:
- n = 2.0 — free space (ideal, no obstacles)
- n = 2.5–3.0 — typical indoor environment (offices, homes)
- n = 3.5–4.0 — heavy obstructions (concrete walls, industrial)
Keep in mind that RSSI-based distance estimation is inherently imprecise. Environmental factors like multipath interference, antenna orientation, human body absorption, and humidity all affect signal propagation. Treat the result as a rough estimate, not a precise measurement.