Use this free online cello tuner to tune up your cello. This is for the standard CGDA cello tuning. For other methods on how to tune your cello go to our Cello Tuning Methods page. Click on the note for the string you want to tune and then adjust the fine tuner, and tuning pegs if necessary, to match it up with the note that is being played. Also you can use this online tuner for your viola, it is the same tuning.
Warning: This online cello tuner produces sounds that are actually 1 octave higher then the cello, i did that because a lot of people dont have very good speakers on their computers and cant produce the rich deep sound of the cello, so I find that it is easier using these tones which are actually 1 octave higher to tune. So what I am saying is dont actually try to tune it to the same octave as these tones or your will break some strings, and nobobdy wants that.