First, estimate the area in square feet that you want the cell phone signal to cover inside your home or office.
Next, determine the strength of the cell phone signal OUTSIDE the building.
The best way to do this is to take actual signal strength readings in decibels (dBm). The 'bars' display on your phone is a graphical approximation of signal strength, and is not sufficiently accurate for this purpose.
All smart phones will provide actual signal strength readings in dBm. On most Android phone models, you can navigate to the Mobile Networks screen in Settings and see your real time signal strength in dBm.
On other devices, including iPhone models, you must place your phone in Field Test Mode in order to see the dBm reading. For tips on accessing the correct screen or the Field Test Mode on your device, refer to this page:
After you have a signal strength reading in dBm, choose the booster model that provides coverage corresponding to your square footage estimate.
However, if the dBm reading outside your home or office is in the -85 to -95 range, indicating an especially weak signal, then you should probably choose the next more powerful booster model to provide coverage for the desired area.
If the dBm reading is weaker than -95 (like -99, for example), then we strongly recommend you contact weBoost Customer Support (1-866-294-1660) to discuss your situation. A signal that weak is difficult to boost, and you should talk with us before buying a booster.