How to Enable Numeric Signal Strength on an iPhone

by Niru S

Toggle between the signal strength bars/dots at the top left corner of an iPhone (running any iOS 4.1 onwards) and it's accurate numeric equivalent.


  • An iPhone running iOS 4.1+
  • Instructions

    Step 1

    Press the Home button to launch the phone's home screen. As you know, the dots on the top left corner of the screen indicate signal strength.

    Step 2

    Tap on Phone > Keypad > Dial *3001#12345#* and tap on Call.

    Step 3

    As soon as you tap the Call button, the Field Test app will open. You’ll notice that instead of the dots, you’ve got a negative number in its place.

    Step 4

    While in the Field Test app, hold down the 'Sleep/Turn Off' button until the 'Slide to Power Off' screen shows up.

    Step 5

    Now, instead of turning the phone off, release the 'Sleep/Turn Off' button and hold the 'Home' button for a couple of seconds till the Field Test exits and it returns you to the Home Screen.

    Step 6

    There you have it! The signal will be displayed as a number. In my case it is -83dBm.

    Step 7

    Reading the display: -50dBm to -60dBm = Strongest signal strength. Greater than -95dBm = Satisfactory signal. Less than -110dBm = Call-dropping bad signal reception.

    Step 8

    To switch back to bars/dots, repeat Steps 2 - 4. Now, tap on the numeric signal strength to change it back to bars/dots. Then press the Home button to exit Field Test mode, and that's that!