What Do Signal Bars on a Cell Phone REALLY Mean?

In all honesty, the bars on a cellphone do not really mean anything. Today, we got a call from a person who asked, "Why does my new Verizon phone have one bar when old one had 3?" That is because antenna signal bars are merely an aesthetic representation of the signal strength. Depending upon the make and the model of the phone, there can be quite a bit of fluctuation between the bars on one phone to another phone. Accurate signal strength is measured in decibels, a unit of signal strength measurement.

For example, if an algorithm of your phone says that for every 10 db you will see a bar and your friend's phone manufacturer has set it such that for every 15 db a bar will appear, their signal will always appear to be weaker even though they may be receiving more dbs (40 dbs which would be 2 bars as opposed to 30 which would show 3 bars). Bars could be compared to a gas gauge where they give you a general idea of what the signal strength is, but not the actual strength.

Therefore, it is more effective to measure signal strength in decibels to determine the best place to find a signal or use a booster. Typical Android phones with have this function in their "settings". Typical iPhones can access this information by putting phone in test mode by typing *3001#12345#* followed by "Call" in the phone's number key pad - The Decibels appear in top left corner or by sliding down from the top edge. -50 dB would mean maximum signal and -110 dB would mean no signal. Your range would be somewhere in the middle of those two numbers.

On a sidenote (nothing to do with "signal bars"): A Hershey bar phone (AKA a slab, block, candybar) takes the shape of a cuboid, usually with rounded corners and/or edges. The name is derived from the rough resemblance to a chocolate bar in size and shape. This form factor was widely used in the 90's and early part of 21st century by a variety of manufacturers including Nokia and Ericsson.