Method for limiting a torque of an electric machine fed by an at least single-phase converter, which machine is converted to active short-circuit operation when the converter is driven incorrectly and into freewheeling operation when a rotational speed threshold is undershot, characterized in that • at least one current actual value of at least one phase current (12, 13) of the machine is detected during active short-circuit operation, • a rotational speed signal (D1, D2) carrying current rotational speed information is derived from the at least one detected current actual value of the at least one phase current (12, 13), • the current rotational speed information of the rotational speed signal (D1, D2) is compared with the pre-specifiable rotational speed threshold, • as soon as the current rotational speed information indicates a rotational speed which lies below the pre-specifiable rotational speed threshold, a switching signal (U, U1, U2) is generated for switching from active short-circuit operation to freewheeling, and • the converter is driven with this switching signal (U, U1, U2), wherein, for deriving the rotational speed signal (D1, D2) carrying the current rotational speed information, • a period duration, in particular between two zero crossings, of the at least one phase current (12, 13) is detected from the at least one detected current actual value of the at least one phase current (12, 13), • at the beginning of each period duration of the at least one phase current (12, 13), at least one time signal (Z1, Z2) is triggered, which ∘ during a prespecified time interval within the period duration of the at least one phase current (12, 13) has a first and ∘ during the remaining period duration of the at least one phase current (12, 13) has a second signal level, • the at least one time signal (Z1, Z2) is continuously averaged over each period duration and an average value of the at least one time signal (Z1, Z2) formed therefrom forms the rotational speed signal (D1, D2) carrying the current rotational speed information. • at least one current actual value of at least one phase current (12, 13) of the machine is detected during active short-circuit operation, • a rotational speed signal (D1, D2) carrying current rotational speed information is derived from the at least one detected current actual value of the at least one phase current (12, 13), • the current rotational speed information of the rotational speed signal (D1, D2) is compared with the pre-specifiable rotational speed threshold, • as soon as the current rotational speed information indicates a rotational speed which lies below the pre-specifiable rotational speed threshold, a switching signal (U, U1, U2) is generated for switching from active short-circuit operation to freewheeling, and • the converter is driven with this switching signal (U, U1, U2), wherein, for deriving the rotational speed signal (D1, D2) carrying the current rotational speed information, • a period duration, in particular between two zero crossings, of the at least one phase current (12, 13) is detected from the at least one detected current actual value of the at least one phase current (12, 13), • at the beginning of each period duration of the at least one phase current (12, 13), at least one time signal (Z1, Z2) is triggered, which ∘ during a prespecified time interval within the period duration of the at least one phase current (12, 13) has a first and ∘ during the remaining period duration of the at least one phase current (12, 13) has a second signal level, ∘ during a prespecified time interval within the period duration of the at least one phase current (12, 13) has a first and ∘ during the remaining period duration of the at least one phase current (12, 13) has a second signal level, • the at least one time signal (Z1, Z2) is continuously averaged over each period duration and an average value of the at least one time signal (Z1, Z2) formed therefrom forms the rotational speed signal (D1, D2) carrying the current rotational speed information.