Methods and apparatus for determining a transmit antenna gain and a spatial mode of a wireless device (100) are disclosed. The apparatus (100) includes a main receive antenna (112) associated with a first receive signal strength, a diversity receive antenna (114) associated with a second receive signal strength, and a transmit antenna (116). Each of the antennas (112, 114, and 116) is operatively coupled to a controller (102). The controller (102) determines (i) a difference between the first receive signal strength and the second receive signal strength, (ii) a correction factor based on the difference, and (iii) the transmit antenna gain based on the correction factor. In addition, the difference between the first receive signal strength and the second receive signal strength may be used, along with other sensor data (e.g., accelerometer), to estimate the spatial mode (e.g., orientation and hand grip) of the device (100). This spatial mode estimation may be then be used, among other things, to more accurately determine transmit antenna gain.