Methods of derating a nonlinear ultrasound field and associated systems are disclosed herein. A method of derating a nonlinear ultrasound field in accordance with an embodiment of the present technology can include, for example, calibrating an ultrasound source to a first source voltage (Vw) and generating a nonlinear acoustic wave from the ultrasound source into water. The method can further include measuring a focal waveform of the nonlinear acoustic wave and determining a second source voltage (Vt) of the ultrasound source that generates the same focal waveform in tissue.