Modern bass clarinets in Bb have a range of Bb1 – B5.

The compass is roughly the same as the bassoon's and an octave below that of the Bb clarinet (D3–Bb6).

Compared to the ambitus of the bass clarinet in Bb usual in Berlioz's day (D2–F5) the modern instrument with its four additional keys reaches a third lower; the keys correspond to the four notes Db2–Bb1 (sounding). However, models are still made with a lowest note of C2 or Db2.

Until the end of the 19th century the bass clarinet was used primarily for bass tasks only; the high notes were only seldom required and ended at F5.

Although the notes Bb5 and B5 are playable they are not asked for in orchestra literature.