If your interested in remixing or mash ups, sooner or later you are going to have to figure out how to calculate the BPMs of a track. Because I'm lazy, I usually do a quick google search for track information, sometimes you'll find someone else has already done the maths for you. Sometimes however, you'll have no choice but to sit down and figure it out the old fashioned way. Fortunately, you don't have to be a member of MENSA to figure out a tracks BPMs. At worst, you'll need a pen, paper and calculator.

Here is a simple step by step overview of how you can go about calculating the BPMs for any given track.

1. Listen carefully to the track, if you can, isolate the drum beat from the rest of the song. As a general rule, most tracks are in 4/4 time, and I'd say this are the easiest to start out with. This is especially true of songs from the techno, electronica and hip hop schools.
2. You can focus in on the bass drum or the hihat. I find the hihat easier.
3. Grab a stop watch, hit play on the track and start on the stop watch at the same time. Start counting, but keep counting past four! Nod the head, get your groove on, that's the beat.
4. Stop the clock after 15 seconds. How many beats have you counted? Multiply that figure by 4, thats the BPM for the track. Here's an example, in 15 seconds I count 25 beats, I multiply 25 by 4 and get 100. In other words, for every 60 seconds, there are 100 beats, or... 100 beats per minute.
5. Now obviously, this method leaves room for human error. I'd recommend repeating the process a handful of times to get it as accurate as possible.

That's it. I'd suggest that this method is easiest for simple 4/4 songs. I'd also suggest that if your new to it, don't start out trying to figure out songs by bands that like to mix up their time signatures, like Tool for example. That's a guaranteed headache!