How to Check Your Cell Phone Signal Strength

How to Check Your Cell Phone Signal Strength

Written By Alejandra Jasso
31st Jan 2024

Bars Don’t Really Reflect Signal Strength

We worship at the altar of strong and steady bars as much as the next person. Signal strength is life! But bars aren't as trustworthy as you may think. Finding out what the bars mean on iPhone or Android may not actually be the best way to do a signal check. Luckily, there is a better way to accurately carry out a signal strength test: Use the field test mode to measure your dBm or decibels level.

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What Is the Difference Between Signal Strength and Signal Quality?

Signal strength is how much signal your phone router or other device is receiving.

Signal quality is how much noise or interference that signal is contending with.

Radio signals are all around us from other cell towers, other calls, other devices, or even appliances. These signals can interfere with your cell phone connection to the tower. The more interference or noise there is, the lower your signal quality will be.

It is possible to have bad signal quality, and good signal strength or bad strength and good quality. Ideally, the two need to be good for clear calls and data. If you have good signal strength, but terrible quality, you will still experience dropped calls, slow data speeds, and breaks in voice.

How to Measure Your Signal Strength in Decibels

Most phones have a “field test mode”. This can be found under your settings app on an Android, or by typing in a code on an iPhone. dBms are represented as rsrp signal strength.

dBm or decibel level is the most accurate way to test 5G, 4G, and LTE. It reflects exactly how much signal your phone is receiving. The field test mode doesn’t need a special app to be accessed, nor does it need your phone to be in a specific place. You can simply walk around your house or office to find the best signal strength.

Across all carriers, decibel readings, measured in decibel-milliwats (dBm) are the same, regardless of the way they choose to show them as “bars”. All carriers and all frequencies are measured in decibel milliwatts or dBm, including 4G, LTE, and 5G.

It is important to note that 5G signal is not available everywhere. Currently, 5G is only for data and all voice is over 4G. When you check your dBms you need to keep in mind that a great 5G signal may not mean great voice quality.

To find your signal strength on your phone, you need to look for the rsrp measurement. Rsrp signal strength is your phone’s way of displaying the current available dBms.

How Do I Find the RSRP Signal Strength on My Phone?

Methods vary from phone to phone, so read on to find step-by-step instructions for your device.

Field Test Mode For iOS Users

To find your iPhone 14, 15 and 16 field test mode, follow these steps:

  1. Turn off your phone's WiFi.
  2. Go to your phone’s “Phone” app and enter: *3001#12345#*. Hit the green button
  3. Choose LTE or Serving Cell Info
  4. Choose “RsrpRsrqSinr”
  5. Rsrp0 is your dBm
  6. Note: rsrp0 is your nearest tower, rsrp1 is your nearest back up tower.


  1. Dial *3001#12345#*
  2. Tap “LTE” on iOS 11-13 or “Menu” on iOS 14 - 16
  3. Tap “Serving Cell Meas”
  4. Your dBm is read as “rsrp0”

Note: This code may not work on all phones.

Field Test Mode for Android Users

The field test mode for Android devices varies by phone model and OS version, but it can usually be found under the Settings menu.

  1. Tap “Settings”
  2. Tap “About Phone”
  3. Tap “Status” or
  4. “Network”
  5. Tap “SIM Status”
  6. Your dBm or rsrp can be found under “Signal strength”

You can also use one of these apps to measure your phone's signal strength.

LTE Discovery: For Android

This is one of the best signal apps on the Play Store. It is packed full of features and is totally customizable. It will not only show you your dB level, but also your nearest cell tower.

Network Cell Info Lite: For Android

Network Cell Info provides the location of your signal on a map. It covers all cell networks, laying them out in easy-to-read color coding. Green = good, red = bad.

Open Signal: For Android and Apple

This great little app shows all nearby signals as an easy-to-understand graphic. Easily measure signal strength, data speeds and signal quality.

Network Signal Pro: For Android

This app gives you a summary of the whole network as well as any extra connections like WiFi laid out in a graphic or a graph. It shows tower locations, dBm strength and average, and other useful info.

What Does RSRP and RSSI Mean for Signal Strength?

RSRP stands for reference signal received power and is displayed in decibel milliwatts. It is the exact amount of signal being received by the device and is used to measure 4G, LTE and 5G. It takes an average of the power of the cell signals that your phone is getting from the tower and shows how strong those signals are. It will be shown on your phone as a dBm reading, between –110 and –50. The closer to –50 you are, the better your signal strength is.

Cellular routers for home or office internet, like the Peplink BR1 Mini and Br1 Pro 5G, also use a rsrp measurement for signal strength. This can be found in the router’s interface, either in it’s app or in your browser. Check your router’s manual to find out how to access the interface.

RSSI or Received Signal Strength Indicator shows how strong a radio signal is. Your phone has an RSSI which shows up as the bars counter. RSSI is a baseline of how strong the signal is after cable and antenna loss. The stronger the RSSI, the stronger your signal is. RSSI is always shown in the negatives, so the closer it is it 0 the better your received signal is.

What Do I Do with My Signal Strength dBm Reading?

Once you’ve tracked down your dBm reading, it’s time to start exploring your surroundings. Take your time walking around the property you’re looking to assess. dBm readings can take up to 30 seconds to refresh, so don’t rush.

The dBm should change based on your location, so keep track of which areas receive the best signal. This information can help you figure out the general direction of your nearest cell phone tower, pinpoint the rooms inside your building that get the best reception.

Here’s a general breakdown of common dBm signal ranges (and their possible bar assignations, depending on carrier/phone manufacturer):

Signal Strength General Results
-50 to -79 dBm Considered great signal (4 to 5 bars)
-80 to -89 dBm Considered great signal (4 to 5 bars)
-90 to -99 dBm Considered average signal (2 to 3 bars)
-100 to -109 dBm Considered poor signal (1 to 2 bars)
-110 to -120 dBm Considered very poor signal (0 to 1 bar)

Hopefully, you can find a spot or two that are close to -50 dBm!

What if My dBm is Lower than -95?

Please accept our condolences for your weak signal. Fortunately, we can direct to a wide selection of cell phone signal boosters to get your phone and smart devices back on track! The right signal booster can capture your weak signal, amplify it, then broadcast that newly boosted signal straight to your phone and devices for crystal clear coverage.

Here are our most popular:

Bolton Victory Yagi/Panel Cellular Signal Booster

Overview of the Bolton Victory Yagi/Panel:

  • For Small to Medium Size Homes and Offices
  • Covers Up to 4,000 Sq Ft
  • Up to +72 dB Gain
  • Up to 26 dBm Uplink Power
  • Supports All Carriers Simultaneously

The Bolton Victory Yagi/Panel cellular booster is our top pick for most weak signal areas. Under optimal conditions, it can blanket up to 4,000 sq ft with stronger cell reception, which is more than enough for most people. Featuring up to 26 dBm uplink and up to 72 dB gain, it has incredible reach and can significantly amplify your existing weak cellular signal.

Strategically paired with the Bolton Quicksilver Outdoor Yagi Antenna, it works wonders in remote locations. This antenna is designed to draw in signals from cell towers up to 5 miles away. Distance from the signal source will no longer be a problem.

While capable of boosting multiple carriers at the same time, you may only receive improved cell reception from one or two carriers. This is because the antenna is directional and needs to point at the closest cell tower that’s powered by your preferred carrier. If boosting multiple carriers is more important than coverage area, consider the Bolton Velocity Omni/Panel Cellular Signal Booster.

Pros: Cons:
  • Meets most people's coverage requirements.
  • Offers max gain allowed by the FCC for multi-carrier boosters, maximizing amplification.
  • Has incredible uplink, allowing greater reach to cell towers.
  • Equipped with powerful Yagi antenna that outperforms the competition.
  • Can only boost one or two carriers at a time because of directional antenna.
  • Will not cover your entire home if the outdoor signal is extremely weak.

Cel-Fi by Nextivity GO X

Overview of the Cel-Fi GO X:

  • For Large Homes and Offices
  • Covers Up to 15,000 Sq Ft
  • Up to +100 dB Gain
  • Amplifies One Carrier at a Time

The GO X by Nextivity is the most powerful cell phone signal booster available. It’s designed with up to 100 dB gain, the highest on the market. This unit can seriously make all your signal woes disappear. The caveat is that it can only boost one carrier at a time. Though, through the Cel-Fi WAVE app, you’re able to switch between carriers as you need.

Super customizable, you have multiple outdoor antenna options to really maximize the amplifier's reach to your closest cell tower.

Rated to cover up to 15,000 sq ft, it's best for large homes and small businesses. Indoor coverage will vary based on the strength of your outside signal.

Pros: Cons:
  • Capable of providing whole-home coverage.
  • Features highest amplification gain on the market.
  • Is extremely customizable to fit any signal environment.
  • Comes with an app that lets you monitor and manage performance.
  • On the pricier side.
  • Only amplifies one cellular provider at a time.

SureCall Flare 3.0

Overview of SureCall Flare 3.0:

  • For Small Homes or Spot Coverage
  • Covers Up to 3,000 Sq Ft
  • Up to +72 dB Gain
  • Up to 26 dBm Uplink
  • Supports All Carriers Simultaneously
  • 2-in-1 Amplifier/Indoor Antenna Combo for Ease of Installation

The SureCall Flare 3.0 cellular booster packs a signal punch for the price. It includes a Yagi antenna, which is ideal for rural areas, and a sleek amplifier. The indoor antenna is built into the amplifier, making the Flare 3.0 one of the easiest units to install yourself.

With up to 72 dB gain and 26 dBm uplink, it offers good amplification and reach to distant cell towers for a booster of its kind. While power is similar to that of the Bolton Victory, the Flare 3.0 offers less coverage and a less powerful Yagi antenna. It’s rated to cover 3,000 sq ft, but will likely only provide multi-room to spot coverage.

Pros: Cons:
  • Budget-friendly.
  • Offers max gain allowed by the FCC for multi-carrier boosters, maximizing amplification.
  • Has incredible uplink, allowing greater reach to cell towers.
  • Features 2-in-1 Amplifier/Indoor making installation a breeze.
  • Paired with Yagi antenna that’s slightly less powerful than the competition.
  • Can only boost one or two carriers at a time because of directional antenna.

Contact Us

Signal Boosters is a leading provider of cell phone signal boosters for homes, vehicles, and commercial buildings. We specialize in consumer-friendly kits as well as customized RF systems for cellular, public safety two-way radio, DAS, and WiFi.

We’re here to assist with any issues you might be experiencing with poor cell service. Contact us today, or call us at 1-800-470-6777.

Interested in Learning More? Check Out Our Cellular Info Hub / WiFi Info Hub

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