RSSI Calculator
Convert between RSSI dBm values and signal quality percentage for wireless links.
About RSSI Calculator
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
Worked example
With the default values below, RSSI Calculator returns Signal Quality of 70.0%. Change any input above and every figure here is recalculated in your browser.
Inputs used
- RSSIaccepts -100–-50 dBm
- -65 dBm
Results
- Signal Quality
- 70.0%
- Quality Rating
- Good
Step by step
- 1Values used
- 2RSSI to quality percentage
- 3Signal Quality= 70.0
- 4Quality Rating= Good
Assumptions and limits
- The result is derived only from the single input listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 1 decimal place, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
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.