"Intonation, in music, is a player's realization of pitch accuracy in music to oneself and across an ensemble. If musicians have "bad intonation", it means they play or sing out of tune. Intonation can also mean tuning.

Strings

In string instruments, intonation is more of a worry than in other instruments. Because most string instruments are unfretted, if a finger is too high or too low by even a fraction of an inch, the note will be out of tune. The process of gaining good intonation typically takes many years of playing to acquire and is arguably the hardest part of learning a stringed instrument."

Ukulele Intonation

People (particularly guitar players) regularly ask, "I want a ukulele with perfect intonation, but I only want to pay a little for it." We reply, "forget it"

Although almost all fretboards on production ukuleles are very accurately cut with a laser cutter that is computer driven, the very short free string length of the ukulele as very unforgiving in regard to perfect intonation. In addition, plastic strings, such as nylon are not as precision as steel strings as found on guitars, banjos mandolins, etc. Plastic string relax and tend to go flat... and really drive you nuts the first couple of weeks after they are installed on an instrument. Futher, intonation depends a lot on the skill of the player. And lastly intonation changes as we change the key in which we play.

The Ukulele is the instrument of "innocent merriment." Nothing more.

Ukuleles are fun instruments. Ukuleles are not acoustic physics laboratories with small sound chambers.

People pay thousands of dollars for custom guitars to improve intonation, but expect the ukulele to match the same precision. It just ain't gonna happen....

When you see a ukulele advertised with "perfect" intonation, you will also see a statement of utter falsehood.

If you are mad at your uke over intonation, try changing the strings to a set of premium brand strings like Aquila or Worth. Sometimes this can do a world of good.

Intonation is how true a note is to pitch as the player moves up the fingerboard. A “true” instrument when properly set up should, at the twelfth fret produce the same note as an open string just on octave higher (e.g. open A string first course 440Hz, twelfth fret 880Hz). Another test is to play a 12th fret "harmonic" and then check it with a fretted 12 fret note. A "true" instrument should hit each note played exactly to what frequency that is required (G=392 Hz, C=261.6 Hz, E=329.6 Hz and so on). Intonation is the most important facet in building a fine instrument. This is followed very closely by playability. Now, how do we achieve intonation? It would be very simple to just double the measurement from the twelfth fret, glue on the bridge and say it close enough, but that ain't so. and never forget that an instrument expands and contracts and wood breathes.

Another factor affecting intonation is an individuals playing style, this will ultimately play a role with the instruments intonation. If the player is a hard strummer and bends his strings during chording (which elongates the strings and throws of the pitch) , the intonation is probably bad news... but the good news is the player is having fun and that is what the ukulele is all about.