Embodiments include apparatuses, methods, and systems associated with biasing a sleep transistor (also referred to as a power gate transistor) in an integrated circuit. The sleep transistor may be coupled between a load circuit and a power rail, the sleep transistor to be on in an active mode to provide the supply voltage to the load circuit, and to be off in a sleep mode to disconnect the load circuit from the power rail. The bias circuit may be coupled to the gate terminal of the sleep transistor to provide a calibrated gate voltage to the gate terminal during the sleep mode. The calibrated gate voltage may be based on a subthreshold leakage current and a gate-induced drain leakage (GIDL) current of the sleep transistor or a replica sleep transistor designed to replicate the leakage current of the sleep transistor. Other embodiments may be described and claimed.