How to find signal strength on iPhone or Android phone in decibels?

The initial step in selecting a cell phone signal booster for your office, home, vehicles or for large building is to identify the strength of the outside signal. When you look at signal strength you also keenly look at the bars in accordance with the phone’s signal indicator, but it is not recommended as an accurate way. Some phones determine their signal strength on a 5-bar scale, while some show 4 bars and others 8. Even though some phones exhibit same number of bars, there is no standardization, so the strength varies from phone to phone even with the same 4 bar signal. These are the assumptions of common people, whereas experts consider measuring signal in decibels. Decibels are defined as a logarithmic units used for measuring the signal strength and are accurate thus making it an ideal solution for communications.
In most of our phones we see Field Test mode in the settings options, which shows information regarding your phone, including the signals strength in decibels. There are some things that you should have in mind while measuring signals in terms of decibels.
The signal reading you choose remains valid only for the phone’s individual carrier.
To obtain readings from other carriers, you’ll have to choose a phone for each carrier.

Keep track of the network (2G, 3G, 4G, LTE, etc.) your phone is connected to, while taking the signal readings.
Sometimes LTE readings are measured completely different from previous generation network so without understanding if a signal is from a LTE network or from the previous network, it’s hard to obtain the results.

iPhone Field Test Mode:
The iPhone Field Test Mode app is a hidden built-in. Follow these steps to access it:
Go into Settings > WiFi and turn WiFi Off.

For iOS 9.3 and above: Go into Settings > Cellular > Cellular Data Options > Enable LTE and turn LTE to Off.
For iOS 9.2 and below: Go into Settings > Cellular > Enable LTE and turn LTE to Off.

Go into the Phone app and switch to the Keypad, as you would do to dial a phone number. Dial *3001#12345#* and press the Call button.

Move to the location where you want to obtain the readings, while taking the signal readings, just wait for 30 to 60 seconds of time and then record your signal’s strength, network type and also the carrier.
Hit the home button, to exit and return your iPhone to a normal status. Go back into the settings option and enable WiFi and LTE. You can view this mode on all iPhone’s that runs IOS 4.1 and all the latest versions.
Follow these instructions if you want to opt for decibels instead of dots:
If you like your iPhone to show numerical signal strength instead of signal bars, you can perform these process. In Field-test mode, you can see a “Slide to Power Off”, when you hold down the power button and release it. Then just be held with your Home button until you have returned to the main app screen. While you use your phone you will view numerical signal strength, and also tap the signal numbers to switch to signal bars, and vice versa. Simply just reboot the phone or re-load Field Test Mode and exit it through the Home button, to exit the permanent field-test mode
Android Field Test Mode:
In Android phones it’s a straightforward task. Go to Settings> About Phone, and you will find your numerical strength under either Network or status, and it all depends upon the model of the phone.
There are some apps that you can download to show your signal strength in decibels along with some other information’s. In app store search by typing “cell signal” and find out the apps available for your device.
Move to the location where you want to obtain the readings, while taking the signal readings, just wait for 30 to 60 seconds of time and then record your signal’s strength, network type and also the carrier.

Use of Field Test Mode:
The use of Field Test Mode in common, is to conduct a special kind of field test called as site survey. If you reside in an area with weak signal strength and you are finding ways to boost your signal, perform a site survey to choose a signal boosting system. The site survey takes several accurate readings in and around in order to calculate to know whether the cellular boosting system will help or not and also to determine what sort of equipment are necessary.
Field Test mode is a useful tool in situations such as- switching from unreliable signal bars to a precise numerical value if you want to assess your smartphone’s signal strength in different places.
A site survey field test is a multi-step process, it isn’t complex, and it’s possible to follow these instructions and undergo field test in and around you home or office, using the field test mode on your phone.

Individual phone test mode screens can also be found here on our site.