CR 3.6cm. For perspective the foot length is 0.6 cm which is about the same length of the embryo in the following picture on the photostream at 3 - 4 weeks developement. You will need to view on black to get a feeling for the detail. Use the magnifying glass button above the photo. Please see other images of Human Developement: www.flickr.com/photos/lunarcaustic/sets/72157617368698808/