A wireless transmitter with Q-factor measurement is presented. In some embodiments, a method of performing a measurement test in a wireless power transmitter includes adjusting an input voltage to a bridge circuit; setting up transistors in the wireless power transmitter to form an LC oscillating circuit that includes a transmit coil and a capacitor circuit; measuring a VDET sinusoidal voltage from the LC oscillating circuit; and determining a result from the VDET sinusoidal voltage. The result can be calculation of a Q-factor and/or determination of presence of a foreign object.