Key takeaways
- About −80 dBm or higher is excellent; weaker than −110 dBm is poor.
- The underlying numbers are standardised in the 4G (LTE) specification, so they compare fairly across phones.
- It is a negative number in dBm, and closer to zero is stronger. −75 dBm is much stronger than −105 dBm.
- RSRQ (dB)Rating −10 or betterGood −10 to −15Fair −15 to −20Poor Worse than −20Very poor.
Signal bars are a rough summary, and every phone draws them differently. If you open your phone's hidden signal menu or a cell-info app, you will see the numbers the network actually works with: RSRP, RSRQ and SINR. Together they tell you how strong your 4G signal is, how clean it is, and why your calls drop even when the bars look fine. This guide explains each one in plain English, with the values that count as good, fair and poor.
Quick answer
- RSRP (Reference Signal Received Power) is 4G signal strength, in dBm. About −80 dBm or higher is excellent; weaker than −110 dBm is poor.
- RSRQ (Reference Signal Received Quality) is signal quality under load, in dB. About −10 dB or better is good; −15 dB or worse is poor.
- SINR (Signal to Interference plus Noise Ratio) is how much the wanted signal stands out from interference, in dB. Above 13 dB is good; below 0 dB is poor.
- Low RSRP means you need more signal (a booster helps). Good RSRP with poor SINR or RSRQ points to interference or congestion.
Why bars aren't enough
There is no standard for bars. One phone might show four bars where another shows two, for exactly the same signal. Bars also show only strength, not quality, which is why you can have "full signal" and still fail to load a page. The underlying numbers are standardised in the 4G (LTE) specification, so they compare fairly across phones.
What is RSRP?
RSRP measures how much power your phone receives from the tower's reference signals, the "beacon" every 4G cell transmits. It is a negative number in dBm, and closer to zero is stronger. −75 dBm is much stronger than −105 dBm.
The scale is logarithmic: every 3 dB is roughly double or half the power, and 10 dB is ten times. So −100 dBm is ten times weaker than −90 dBm. That is why a booster's gain in dB makes such a difference indoors.
| RSRP (dBm) | Rating | What you will experience |
|---|---|---|
| −80 or higher | Excellent | Fast data, perfect calls |
| −80 to −90 | Good | Reliable calls and good data |
| −90 to −100 | Fair | Usable; speeds drop, especially in inner rooms |
| −100 to −110 | Poor | Slow data, occasional call drops |
| Weaker than −110 | Very poor | Frequent drops, often no 4G |
Our signal strength checker lets you rate your own reading instantly.
What is RSRQ?
RSRQ compares the useful reference signal with everything else your phone receives on that channel, including other cells and traffic. It is measured in dB, usually between about −3 and −20, and closer to zero is better. RSRQ falls when the cell is heavily loaded or when nearby cells interfere.
| RSRQ (dB) | Rating |
|---|---|
| −10 or better | Good |
| −10 to −15 | Fair |
| −15 to −20 | Poor |
| Worse than −20 | Very poor |
What is SINR?
SINR is the ratio between the signal you want and the interference plus background noise. It is in dB, and higher is better. SINR is the number that best predicts your data speed, because the phone chooses its data rate (its "modulation") according to how clean the signal is.
| SINR (dB) | Rating | Typical result |
|---|---|---|
| 20 or higher | Excellent | Top speeds the cell can offer |
| 13 to 20 | Good | Fast, stable data |
| 0 to 13 | Fair to poor | Noticeably slower, video may buffer |
| Below 0 | Poor | Interference is stronger than your signal; drops likely |
Reading the three numbers together
| RSRP | SINR / RSRQ | Diagnosis | What helps |
|---|---|---|---|
| Weak | Poor | Not enough signal reaching you, typically indoors or far from the tower | A signal booster with a well-placed outdoor antenna |
| Strong | Poor | Interference from several towers, common on high floors, or a heavily loaded cell | A booster with a directional antenna locked onto one tower; Wi-Fi at peak hours |
| Weak | Good | Clean but faint signal, typical of rural homes far from a tower | A booster works very well here |
| Strong | Good | Signal is not your problem | Check the phone, SIM, plan or tower congestion |
For the "strong but poor" case, read why upper floors get weak signal; for slowdowns only at busy hours, see weak signal vs network congestion.
How to see these numbers on your phone
- Android: Settings → About phone → SIM status shows signal strength in dBm (this is usually RSRP on 4G). For RSRQ and SINR, use a free cell-info app or, on many Samsung phones, dial *#0011#.
- iPhone: dial *3001#12345# and press call to open Field Test Mode, then look for rsrp, rsrq and sinr in the serving cell section.
Our step-by-step guide on finding your 4G band shows these menus in more detail.
What do the numbers mean for a signal booster?
A booster amplifies the signal its outdoor antenna receives. Two practical rules:
- Measure outside, not just inside. Take an RSRP reading on the roof or balcony. Around −100 dBm or better outside is usually enough for a booster to give good indoor coverage; weaker outdoor signal calls for a higher-gain outdoor antenna or a stronger kit.
- Look at SINR outside too. A booster amplifies whatever the outdoor antenna hears, so a directional antenna aimed at one tower gives a cleaner result than an omnidirectional one where several towers interfere.
Kits such as the SIGLIFT SL-850-27DB are designed for weak outdoor signal over large areas; compact kits suit smaller homes with decent outdoor readings. Compare them all in our booster comparison table.
Frequently asked questions
Is −110 dBm RSRP good or bad?
It is poor. At −110 dBm, 4G is barely holding: expect slow data and dropped calls, especially when you move between rooms. Anything stronger than about −90 dBm is comfortable.
Why is my RSRP good but internet slow?
Look at SINR and RSRQ. If they are poor, interference or a busy cell is slowing you down, not weak signal. If they are good too, the slowdown is probably congestion at peak hours or a problem with the tower's own connection.
Is RSSI the same as RSRP?
No. RSSI measures the total power on the channel, including noise and interference, while RSRP measures only the cell's reference signal. RSRP is the better number for judging 4G coverage.
What SINR do I need for HD video calls?
There is no single cut-off, but SINR above about 10–13 dB with fair-or-better RSRP usually gives smooth HD video calls. Below 0 dB, calls tend to freeze or drop.
Can a signal booster improve SINR?
Indoors, yes: a booster fed by a directional outdoor antenna replaces a weak, noisy indoor signal with a strong, clean one from a single tower. It can't fix interference or congestion at the tower itself.
Got a screenshot full of numbers? WhatsApp it to SIGLIFT at +91-9650237601 and our engineers will tell you what it means and whether a booster will help, free of charge.
Written by the SIGLIFT technical team — mobile signal booster specialists for Indian networks. Last updated . Questions? Talk to us.
