If you are using metered internet service either through an official Personal Wi-Fi Hotspot service, a jailbroken iPhone WiFi hotspot, or a local cable or telecom monopoly that’s imposing bandwidth caps and limits on your internet access, or any other bandwidth restricted service, you’ll probably want to keep an eye on your bandwidth consumption so that you know where you are and when you may hit your limit. We’re going to show you how you can watch your bandwidth in Mac OS X for free by using an app called SurplusMeter.

How to Monitor Bandwidth Use on your Mac

A free utility called SurplusMeter or BitMeter, either of which runs atop Mac OS X and tracks all network traffic that is being sent and received, which makes tracking bandwidth really easy. Follow the simple steps below and you’ll be watching your internet consumption in a few moments:

First, get BitMeter or SurplusMeter 2.0.3, we’re going to focus mostly on SurplusMeter, and install the app into /Applications Launch your monitoring app (BitMeter or SurplusMeter) Set the day that your monthly billing cycle or bandwidth use starts on (most people will use 1) Set your download cap limit and whether or not to include uploads in your allotted bandwidth Set your connection type (ethernet, AirPort, etc)

After all your settings are squared away, SurplusMeter will start to monitor all up and down network traffic from your Mac. You may notice a “SurplusMeterAgent” running in Activity Monitor’s task manager too, that’s normal and launches automatically on system boot.

The main problem I see with SurplusMeter is that it doesn’t seem to differentiate between local network and internet traffic. If you transfer large amounts of data from your Mac to something else like a media center or Apple TV, you may need to manually tweak the bandwidth use or ‘pause’ SurplusMeter during large LAN file transfers.

You can also get this kind of data from most routers, but for most people it’s not as user friendly. So SurplusMeter isn’t perfect and it’s a little outdated, but it does work fine in Mac OS X 10.6.6, and it’s free so how much can we complain? It would be great if the developer updated it a bit and then submitted for the Mac App Store, there’s clearly an audience for this kind of tool now.

I would say this app is absolutely essential for any Mac user that is faced with a bandwidth cap. Thanks to MacGasm for finding this utility.