On all clarinets the written compass ranges from E3 – C7.

On the C clarinet this is also the range of sounding pitches.
The clarinet in Bb has a range from D3 – Bb6 (to G6 in orchestral playing).
The clarinet in A has a range from C#3 – A6 (to F#6 in orchestral playing).

Some clarinets possess an extra half tone in the low register: these instruments have a slightly longer tube with an Eb key (produces a Db3 on the Bb clarinet).

In modern compositions microtones (e.g., quarter tones) are also asked for. On both the clarinet and the oboe they can be performed either by altering the embouchure or by using special fingerings, usually cross-fingerings.

Microintervals are intervals that are smaller than a half tone. Fingering charts for microtones on the clarinet (e.g., B. Bartolozzi: “New sounds for Woodwinds”, 1967; Caravan; Rehfeldt) give fingerings for the same tone which are often very different and must therefore be tried by the clarinetist.