What’s the lowest signal level for a cell phone signal booster?

Cell phone signal boosters are awesome, but they aren’t magic. I mean, I wish they were. I wish they could create cell signals when there aren’t any, but they can’t. In order to do that you’d need a microcell (which no one sells anymore) or a cell tower on your property. As I found out, trying to get your own cell tower isn’t easy.

That’s right, using a cell booster requires you to have at least some cell signal outdoors. If you have as little as one bar, you could have five bars indoors with the right equipment. But, you shouldn’t try to judge by the bar measurements on your phone. They’re notoriously inaccurate and you don’t even know what’s being measured. Often times you’re being shown the signal strength for basic voice calls when you use HD-Voice and data. That’s totally useless.

Start with getting a cell meter

This WilsonPro cellular signal meter is one of my favorites. You can pay more for a meter, but you probably don’t need to. This will tell you signal strengths of all the major frequencies used by cell boosters. It won’t tell you if those signals are usable (you’ll need the more expensive CellLinq meter for that) but generally if there is a signal, it’s a usable signal.

It may seem silly to spend money on a cellular signal meter for one or two uses. And I get that. But, it’s a useful tool and not that expensive. If you consider it as part of the overall cell booster purchase, you’ll find it’s worth it. Plus, once you get one, you’ll want to take it with you from place to place and tell people how bad their service is.

If that meter is still a bit too expensive you can use something like the Signal Strength app from Google Play. It’s a little light on features but for free, it does give you something. Unfortunately there isn’t a similar app for iPhones.

Once you get a meter, it just takes a Google search to find out what frequencies are used by your carrier in your area. Measure those while standing on your roof, and you’ll get a good idea of the signal available to your booster.

Time for the numbers

In general, you want to see signal strength numbers of -95 to -100dB in order to use a cell phone signal booster. Weaker numbers (like -110 or -115) are not going to give you reliable service. Again, you’ll need to check the internet or a cell tower app to see what frequencies are use in your area.

However, in order to get the best value from your cell phone signal booster, you’ll want signal in the -85dB range or stronger (like -75dB for example.) Remember these are negative numbers, so a number closer to zero means a stronger signal.

With a stronger outdoor signal, the amplifer part of the cell booster system will work better, allowing you to cover a larger area. With a weak signal like -110dB I recommend getting a more powerful booster to compensate. Otherwise you won’t cover the whole area you want to cover.

Get the cell phone signal booster of your dreams from Solid Signal

SolidSignal.com is your source for cell phone signal boosters. You’ll find boosters for small areas like cars or SUVs, all the way up to boosters that can cover 60,000 square feet. If you’re not sure what booster to choose, call us! The number is 888-233-7563 and we’re here during East Coast business hours. If you’d rather do it all electronically, fill out the form below and we’ll get back to you, usually within one business day.

About the Author

Stuart Sweet
Stuart Sweet is the editor-in-chief of The Solid Signal Blog and a "master plumber" at Signal Group, LLC. He is the author of over 8,000 articles and longform tutorials including many posted here. Reach him by clicking on "Contact the Editor" at the bottom of this page.