Method for determining losses, in particular a converterrelated loss component of the total losses, of at least a first and a second drive, wherein the first drive comprises a first motor, i.e. a three-phase electric motor, in particular a synchronous motor, fed by a pulse-width-modulated converter, wherein the second drive comprises a second motor, i.e. a three-phase electric motor, in particular a synchronous motor, fed by the converter, wherein the first motor has a number of windings w_1 and a wire cross-section A1 of its winding wire of its stator winding, and the second motor has a number of windings w_2 and a wire cross-section A2 of its winding wire of its stator winding, wherein the wire cross-section A2 is equal to the product of the wire cross-section A1 and the quotient of the number of windings w_1 and the number of windings w_2, wherein in a first method step the losses P HL _1 of the first drive are determined according to P HL _ 1 = 3 ⋅ U DC 2 w _ 1 2 ⋅ g f PWM * m, wherein w_1 is the number of windings of the first motor, wherein U DC is the DC link voltage of the converter, wherein g f PWM ∗ m = ∑ i ∑ j h fi j ⋅ g i, j 2 m, and g f PWM ∗ m can be designated as a characteristic function, wherein i and j number the frequencies f i,j, in particular the non-vanishing frequencies f i,j, in the Fourier spectrum of the supply voltage of the first motor, in particular which is detected, wherein h fi j = cosφ Z fi j ⋅ w 1 2, wherein cos(Φ) is the power factor dependent on the frequencies f i,j, and Z is the impedance of the first motor dependent on the frequencies f i,j, and these are detected as a function of the frequencies f i,j, wherein g i,j ( m) is a standardized output voltage of the converter, in particular as a function of the degree of modulation m, at the respective frequency f i,j, wherein the standardized output voltage g i,j ( m) is determined from U i, j = U DC ⋅ g i, j m, wherein the voltage components U i,j are determined from the Fourier spectrum of the supply voltage of the motor, wherein in a second method step the losses P HL _2 of the second drive are determined according to P HL _ 2 = 3 ⋅ U DC 2 w _ 2 2 ⋅ g f PWM ∗ m, wherein w_2 is the number of windings of the second motor, in particular wherein the characteristic function g f PWM ∗ m determined for the first motor is used as the characteristic function g f PWM ∗ m. wherein the first drive comprises a first motor, i.e. a three-phase electric motor, in particular a synchronous motor, fed by a pulse-width-modulated converter, wherein the second drive comprises a second motor, i.e. a three-phase electric motor, in particular a synchronous motor, fed by the converter, wherein the first motor has a number of windings w_1 and a wire cross-section A1 of its winding wire of its stator winding, and the second motor has a number of windings w_2 and a wire cross-section A2 of its winding wire of its stator winding, wherein the wire cross-section A2 is equal to the product of the wire cross-section A1 and the quotient of the number of windings w_1 and the number of windings w_2, wherein in a first method step the losses P HL _1 of the first drive are determined according to P HL _ 1 = 3 ⋅ U DC 2 w _ 1 2 ⋅ g f PWM * m, wherein w_1 is the number of windings of the first motor, wherein U DC is the DC link voltage of the converter, wherein g f PWM ∗ m = ∑ i ∑ j h fi j ⋅ g i, j 2 m, and g f PWM ∗ m can be designated as a characteristic function, wherein i and j number the frequencies f i,j, in particular the non-vanishing frequencies f i,j, in the Fourier spectrum of the supply voltage of the first motor, in particular which is detected, wherein h fi j = cosφ Z fi j ⋅ w 1 2, wherein cos(Φ) is the power factor dependent on the frequencies f i,j, and Z is the impedance of the first motor dependent on the frequencies f i,j, and these are detected as a function of the frequencies f i,j, wherein g i,j ( m) is a standardized output voltage of the converter, in particular as a function of the degree of modulation m, at the respective frequency f i,j, wherein the standardized output voltage g i,j ( m) is determined from U i, j = U DC ⋅ g i, j m, wherein the voltage components U i,j are determined from the Fourier spectrum of the supply voltage of the motor, wherein in a second method step the losses P HL _2 of the second drive are determined according to P HL _ 2 = 3 ⋅ U DC 2 w _ 2 2 ⋅ g f PWM ∗ m, wherein w_2 is the number of windings of the second motor, in particular wherein the characteristic function g f PWM ∗ m determined for the first motor is used as the characteristic function g f PWM ∗ m.