A hybrid TOA positioning system can be implemented to improve location estimation of a wireless network device. An initial location of the wireless network device can be calculated based on locations of a plurality of reference network devices. A first intermediate location of the wireless network device and an intermediate distance calibration constant can be determined based, at least in part, on the initial location of the wireless network device and distance between the wireless network device and each of the reference network devices. A second intermediate location of the wireless network device and a target distance calibration constant can be calculated based on the locations of the reference network devices, the first intermediate location, and/or the intermediate distance calibration constant. The location of the wireless network device can be iteratively estimated based, at least in part, on the second intermediate location and the target distance calibration constant.