Learning library
Instrument Tuning Guides
Understand guitar frequencies, learn how an online tuner detects pitch, and solve the most common reasons an instrument will not stay in tune.
These guides explain the measurements behind the tuner and turn them into practical steps. Start with the frequency chart if you need a reference, the tuner guide if you want to understand pitch detection, or the troubleshooting guide if your guitar will not hold its tuning.
Guitar String Frequency Chart
Standard tuning notes, octaves, exact frequencies, and examples of what a slightly flat or sharp reading means.
Read the frequency guide →How an Online Tuner Works
Follow the signal from your microphone through pitch detection to the note and tuning direction shown on screen.
See how pitch detection works →Why Guitars Go Out of Tune
Diagnose fresh strings, slipping windings, nut friction, temperature changes, tremolo movement, and intonation problems.
Troubleshoot your guitar →All frequency values in these guides assume twelve-tone equal temperament and concert pitch A4 = 440 Hz unless stated otherwise.