This picture shows how big Makemake is. Compare it to the first three dwarf planets (Pluto, Eris, and Ceres) and to Earth and its moon (Luna). Makemake is smaller than both Pluto and Eris. It is larger than Ceres. Makemake has a diameter between 1,300 km and 1,900 km. None of the distances between objects in this picture are to scale.
Images courtesy of NASA, ESA, JPL, and A. Feild (STScI).