Earth vs Moon: size comparison
Earth: 12,742 km. Moon: 3,475 km. Both silhouettes are drawn at the same scale.
Size ratio: ×3.7
Earth
12,742 km
What is measured Mean diameter of the Earth
Earth's equator is about 40,075 km around.
Source : Wikipedia — Earth
Moon
3,475 km
What is measured Mean diameter of the Moon
It drifts away from Earth by about 3.8 cm a year.
Source : Wikipedia — Moon