The carving on the mountain is widely thought to be 190 feet x 90 feet, provided by their official website as well as on Wikipedia. However, based on measurements made in Google Earth, Peter believed the actual size to be closer to 167′ x 77′. After repeated inquiries, Stone Mountain Park was able to confirm the actual size of the carving at 158′ x 76′ — even smaller than he had suggested (though still quite massive).
It’s also widely advertised that the total cutout on the mountain covers 3 acres. As it turns out, the cutout are is roughly 359′ x 191′ which amounts to 1.57 acres.
Peter’s new model just recently went live in the 3D Warehouse, so you can use this KML file to fly there and see it in Google Earth.