A good RSSI signal strength for Wi-Fi is between -50 dBm and -60 dBm, which provides fast, reliable connections for most activities. For cellular networks, anything stronger than -65 dBm is considered good. RSSI (Received Signal Strength Indicator) is measured in decibels-milliwatts (dBm) on a negative scale, so numbers closer to zero are stronger. A reading of -30 dBm is excellent, while -90 dBm is nearly unusable.
How the dBm Scale Works
RSSI values are expressed in dBm, which measures the power of a radio signal relative to one milliwatt. Because wireless signals are extremely weak by the time they reach your device, these numbers are always negative. The key thing to remember: the closer the number is to zero, the stronger your signal. So -40 dBm is much stronger than -80 dBm.
The scale is logarithmic, not linear. That means a drop from -50 to -60 dBm isn’t a small 10-unit decrease. It represents a tenfold reduction in signal power. This is why your connection can feel perfectly fine at -55 dBm and then noticeably sluggish at -70 dBm, even though the numbers don’t look that far apart.
One complication worth knowing: the IEEE 802.11 standard allows devices to report RSSI on a scale from 0 to 255, and each manufacturer defines its own maximum value. This means two different phones or laptops sitting in the same spot can report slightly different RSSI readings. When you’re comparing numbers, make sure you’re looking at the dBm value rather than an arbitrary signal bar count.
Wi-Fi Signal Strength Ranges
For Wi-Fi, signal strength falls into clear tiers that predict what your connection can handle:
- -30 dBm: Extremely strong. You’re essentially right next to the router.
- -50 to -60 dBm: Strong signal, ideal for streaming, video calls, gaming, and large downloads.
- -60 to -70 dBm: Good enough for browsing and standard streaming, though performance may dip slightly.
- -70 to -80 dBm: Fair. Expect slower speeds, higher latency, and more trouble in congested environments with many nearby networks.
- Below -90 dBm: Very poor, likely unusable for any stable connection.
If you’re working from home and rely on video calls, aim for at least -60 dBm at your desk. Basic web browsing and email can tolerate -70 dBm without much frustration. You can check your current signal on most devices through Wi-Fi settings or a free app like Wi-Fi Analyzer.
Cellular Signal Strength Ranges
Cellular networks use RSSI too, but the “good” thresholds differ depending on the generation of network you’re connected to. For 2G and 3G connections, the scale is more forgiving:
- -70 dBm or stronger: Excellent
- -70 to -85 dBm: Good
- -85 to -100 dBm: Fair
- -100 to -110 dBm: Poor
- Below -110 dBm: Very poor
For 4G LTE and 5G, RSSI thresholds are tighter because these networks carry more data and are more sensitive to signal degradation. Anything stronger than -65 dBm is excellent, -65 to -75 dBm is good, -75 to -85 dBm is fair, and below -95 dBm is very poor.
Modern 4G and 5G networks also use a more precise measurement called RSRP (Reference Signal Received Power), which isolates just the reference signal rather than the entire channel. If you’re troubleshooting cellular performance, RSRP gives a cleaner picture. For RSRP, -80 dBm or stronger is excellent, and anything below -100 dBm is poor.
Bluetooth Signal Strength
Bluetooth RSSI works the same way but over much shorter distances. At close range (within a meter or two), you’ll typically see values near 0 dBm. As you move 15 to 25 meters away, readings can drop to around -50 dBm. Below that, connections become unreliable.
Bluetooth RSSI is commonly used for proximity sensing, like detecting whether a device is nearby for automatic unlocking or tracking purposes. The readings are less precise than Wi-Fi RSSI for distance estimation because Bluetooth signals bounce off walls, furniture, and even your body in unpredictable ways. A reading of -10 dBm generally means the device is within arm’s reach, while -40 dBm or lower suggests it’s across the room or further.
Why Strong Signal Doesn’t Always Mean Fast Connection
RSSI tells you how much signal your device is receiving, but it doesn’t account for noise. In a quiet radio environment, a signal of -65 dBm works perfectly. In a noisy environment (a crowded apartment building, an office full of wireless devices, or near a microwave), that same -65 dBm signal can produce a frustratingly slow connection.
The metric that captures this is Signal-to-Noise Ratio, or SNR. It’s the gap between your signal strength and the background noise level. A -65 dBm signal with a noise floor of -90 dBm gives you an SNR of 25 dB, which is solid. That same -65 dBm signal with a noise floor of -80 dBm gives you only 15 dB of SNR, and you’ll notice dropped packets and sluggish speeds. For reliable data use, aim for an SNR of at least 20 dB. Voice and video calls perform best at 25 dB or higher.
This is why moving closer to your router sometimes doesn’t fix a bad connection. If the problem is interference from neighboring networks or electronic devices rather than raw signal strength, you may need to switch your router to a less congested Wi-Fi channel instead.
Quick Reference by Use Case
The “good enough” threshold depends entirely on what you’re doing:
- Video calls and VoIP: -60 dBm or stronger, with SNR above 25 dB
- HD streaming: -60 dBm or stronger
- Web browsing and email: -70 dBm or stronger
- Smart home devices (sensors, plugs): -70 to -80 dBm is usually fine since these send tiny amounts of data
- Barely functional: -80 to -90 dBm, with frequent dropouts likely
If you’re testing signal strength around your home to figure out where to place a router or whether you need a mesh system, walk to the spots where you actually use your devices and check the dBm reading there. A single measurement at the router tells you nothing useful. What matters is the signal at your couch, your desk, and your back bedroom.