RSSI to dBm Converter
Convert between RSSI, dBm, and milliwatts. Check Wi-Fi signal strength quality.
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Wi-Fi Signal Strength Reference
| dBm Range | Quality | Typical Use |
|---|---|---|
| -30 to -50 dBm | Excellent | Same room, line of sight |
| -51 to -60 dBm | Very Good | Nearby room, minimal obstacles |
| -61 to -67 dBm | Good | Video calls, streaming target |
| -68 to -75 dBm | Fair | Browsing, IoT devices |
| -76 to -85 dBm | Weak | Edge of coverage |
| -86 to -90 dBm | Very Weak | Near noise floor, unreliable |
Understanding RSSI and dBm
What Is RSSI?
RSSI (Received Signal Strength Indicator) is a measurement of radio signal power at the receiver. While it is commonly used to gauge Wi-Fi signal quality, RSSI is a vendor-specific relative index rather than a standardized unit. One manufacturer's RSSI scale may range from 0 to 60, while another uses 0 to 255. This inconsistency makes RSSI unreliable for comparing signal strength across different equipment.
Why dBm Is Better
dBm (decibels relative to one milliwatt) is an absolute, standardized power measurement. A dBm value of -50 means exactly the same signal power regardless of the vendor, chipset, or tool. Modern Wi-Fi analyzers and operating system tools increasingly report signal strength directly in dBm rather than a vendor-specific RSSI value. The scale is logarithmic and negative — closer to zero means a stronger signal.
Conversion Formulas by Vendor
- Windows netsh: dBm = (Signal% ÷ 2) - 100 (e.g., 70% = 35 - 100 = -65 dBm)
- Broadcom: dBm = RSSI - 95 (e.g., RSSI 30 = 30 - 95 = -65 dBm)
- Atheros / Qualcomm: dBm = RSSI - 100 (e.g., RSSI 35 = 35 - 100 = -65 dBm)
- Direct dBm: No conversion needed — the value is already in dBm
How to Check Your Wi-Fi Signal Strength
On Windows 11, open PowerShell or Command Prompt and run netsh wlan show interfaces. Look for the "Signal" line which shows a percentage. Use this calculator with the "Windows netsh" vendor setting to convert it to dBm. On macOS, hold the Option key and click the Wi-Fi icon to see RSSI in dBm. On Android, use Wi-Fi Analyzer apps. On iOS, use the AirPort Utility or field test mode.
Optimizing Wi-Fi Signal Strength
If your signal is below -67 dBm in critical areas, try these fixes: move the access point to a central, elevated location away from metal objects and thick walls; reduce interference by switching to a less congested channel (use a Wi-Fi analyzer to find the cleanest channel); add a mesh node or additional access point for coverage in weak areas; upgrade to Wi-Fi 6 (802.11ax) for better range and throughput; or use a wired Ethernet backhaul for mesh nodes instead of wireless backhaul.
Herramientas Relacionadas
Frequently Asked Questions
What is a good RSSI value for zoom or video calls?
For reliable video calls, aim for -67 dBm or better. Zoom recommends at least 2.5 Mbps upload/download for HD video, which requires a signal better than approximately -65 dBm on 5 GHz or -70 dBm on 2.4 GHz in most environments. If your signal drops below -70 dBm, expect pixelation, freezing, or dropped calls.
Can I improve RSSI without buying new hardware?
Yes. Reposition the router to a central, elevated location away from walls, metal objects, fish tanks, and microwaves. Adjust the antennas (if external) to a 45-degree angle. Change the Wi-Fi channel to one with less interference. Update the router firmware and client drivers. Switch between 2.4 GHz and 5 GHz bands as needed. These changes can improve RSSI by 5-15 dB in many cases.
What is the noise floor in Wi-Fi?
The noise floor is the baseline level of ambient radio frequency energy in the environment, typically around -90 to -100 dBm for Wi-Fi channels. A signal below the noise floor cannot be decoded. The signal-to-noise ratio (SNR) is the difference between the signal (RSSI) and the noise floor. An SNR of 25 dB or higher is needed for reliable high-speed Wi-Fi connections.
Does 5 GHz have worse RSSI than 2.4 GHz?
Yes. 5 GHz signals attenuate faster through walls and obstacles than 2.4 GHz. A typical 5 GHz signal may measure 10-20 dBm lower than the same access point's 2.4 GHz signal at the same location. However, 5 GHz usually offers higher throughput because of wider channels, less interference, and more available spectrum. The trade-off is range for speed.
What RSSI value triggers Wi-Fi roaming?
Most Wi-Fi clients start scanning for a better access point when RSSI drops below -70 dBm to -75 dBm. Some enterprise clients roam at -65 dBm for aggressive handoff, while consumer devices may wait until -80 dBm. Mesh systems typically use -70 dBm as the roaming threshold. Lower (more aggressive) thresholds provide better performance but more frequent roaming.