Quaoar is thought to be an oblate spheroid around in diameter, being slightly flattened in shape. The estimates come from observations of stellar occultations by Quaoar, in which it passes in front of a star, in 2013 and 2019. Given that Quaoar has an estimated oblateness of and a measured equatorial diameter of , Quaoar is believed to be in hydrostatic equilibrium, being described as a Maclaurin spheroid. Quaoar is about as large and massive as (if somewhat smaller than) Pluto's moon Charon. Quaoar is roughly half the size of Pluto.
