RSSI Calculator
Convert RSSI (dBm) to a signal quality percentage and rating.
Inputs
Signal Quality
70.0%
Quality Rating
Good
Step by step
Values used
RSSI = -65 dBm
RSSI to quality percentage
quality% = 2 × (RSSI + 100), valid for RSSI between -100 and -50 dBm
Signal Quality
= 70.0
Quality Rating
= Good
How it works
RSSI (Received Signal Strength Indicator) in dBm is commonly mapped to a 0-100% quality scale using a linear formula over the practical usable range of -100 dBm (unusable) to -50 dBm (excellent): quality% = 2 × (RSSI + 100). This mapping is a convention used by many WiFi drivers and utilities (not a physical law), chosen because -50 dBm and stronger is essentially always excellent, and -100 dBm is at or below the noise floor where a connection is effectively unusable.
Formula
RSSI to quality percentage
quality% = 2 × (RSSI + 100), valid for RSSI between -100 and -50 dBm
- RSSI
- Received signal strength in dBm
Frequently Asked Questions
Why does the formula use -100 and -50 dBm as the bounds?
-50 dBm or stronger is treated as the ceiling for 'perfect' signal (100%) since further gains don't meaningfully improve connection quality, and -100 dBm is near or below the typical WiFi receiver noise floor, treated as the floor (0%, unusable).
Is this percentage a universal standard?
No — it's a common convention (used in various OS and driver signal-quality displays) rather than a physical or IEEE standard. Different vendors sometimes use slightly different mapping curves or bounds for their quality bars.
What RSSI is considered a good WiFi signal?
Roughly -65 dBm or stronger (about 70%+ on this scale) is generally considered good for reliable, high-throughput WiFi. Below -80 dBm (about 40% or less), expect noticeably reduced speeds and possible drops.
How is RSSI different from SNR?
RSSI measures absolute received signal power regardless of background noise. SNR measures how far that signal sits above the noise floor, which is actually the better predictor of usable throughput — a strong RSSI in a noisy environment can still perform poorly.