A switched capacitor voltage converter circuit includes: a switched capacitor converter, a control circuit and a zero current estimation circuit. The switched capacitor converter includes at least one resonant capacitor, switches and at least one inductor. The zero current estimation circuit is coupled to the at least one inductor and/or the at least one resonant capacitor, for estimating a time point at which a first resonant current is zero during a first process and/or a time point at which a second resonant current is zero during a second process according to a voltage difference between two ends of the inductor, and/or a voltage difference between two ends of the resonant capacitor, to a generate a zero current estimation signal accordingly for generating the operation signal.