AbstractIf an input‐affine single‐input single‐output control system has a well‐defined relative degree, there exists a (local) change of coordinates transforming the system into the Byrnes‐Isidori normal form. By this transformation, the system is decomposed into two subsystems. The first subsystem can be linearized by feedback, and the second subsystem does not directly depend on the input. To achieve this structure, the last components of the transformation have to fulfill a partial differential equation. Practically, the appropriate choice of these coordinates is usually left to the (experienced) user. In this note, the author suggests a direct calculation based on the computation of flows of certain vector fields. (© 2017 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)