Methods, systems, and devices for head wearable display devices are described. A device may capture a set of images over a set of orientations using a set of cameras positioned on an outward facing surface of the device. The set of images include a first subset of images captured by a first camera and a second subset of images captured by a second camera. The device may detect a set of facial features in each of the first subset of images and the second subset of images, and measure a set of inter-pupillary distances over the set of orientations based on the set of facial features in each of the first and second subset of images. The device may determine an inter-pupillary distance parameter based on aggregating the set of inter-pupillary distances over the set of orientations. The device may calibrate based on the inter-pupillary distance parameter.