Body size can have an immense impact on the biology, ecology, and social status of an animal, but so too can ones ability to advertise or assess body size. Many species communicate their size vocally. Research investigating vocal communication of physical size in mammals, including humans, has focused on two salient and largely independent features of the voice: fundamental frequency and/or corresponding harmonics (perceived as voice pitch) and formant frequencies (resonance frequencies of the supralaryngeal vocal tract). In this talk, I will discuss the degree to which fundamental and formant frequencies reliably predict variation in body size controlling for sex and age, and their relative role in the perception or accurate estimation of body size in humans. The findings that I will present corroborate work on many other mammals whose mechanisms of vocal production, including anatomical constraints on size exaggeration, parallel those of humans. However, my findings also highlight the impact of psychoacoustic, sociocultural and perceptual biases on size communication in humans.