How do I find the BPM of an acoustic or piano version of a song?

I have to do this thing where I listen to songs 60 BPM or less to help my brain. I have acoustic and piano versions of songs I normally listen to but I don't know how to tell how many BPMs they are because they don't have drums. How do I do this?

Richard2015-01-26T11:56:46Z

Use a metronome and adjust it until it matches up. Let the metronome play first near where you think the bpm of the song is start the part of the song where the music comes in on the 1 count of the metronome see if they match. Adjust the metronome and try again until you get it to match.

steve2015-01-26T12:26:41Z

In a pinch you can use one of these online metronomes --

http://www.metronomeonline.com/
http://www.8notes.com/metronome/
http://a.bestmetronome.com/
http://www.webmetronome.com/

Korg, Wittner and Seiko make inexpensive, quality metronomes