  We theoretically study current-induced orbital magnetization in a chiral
crystal. This phenomenon is an orbital version of the Edelstein effect. We
propose an analogy between the current-induced orbital magnetization and an
Amp\`ere field in a solenoid in classical electrodynamics. In order to quantify
this effect, we define a dimensionless parameter from the response coefficient
relating a current density with an orbital magnetization. This dimensionless
parameter can be regarded as a number of turns within a unit cell when the
crystal is regarded as a solenoid, and it represents how "chiral" the crystal
is. By focusing on the dimensionless parameter, one can design band structure
which realizes induction of large orbital magnetization. In particular, a Weyl
semimetal with all the Weyl nodes close to the Fermi energy can have a large
value of this dimensionless parameter, which can exceed that of a classical
solenoid.
