How big is the moon? July 25, 2020 by Pamela Landy The moon’s diameter is 2,160 miles. The earth’s diameter at the equator is 7,926.68 miles. Related Answers If the moon passes between the earth and the sun every month, why doesn’t it eclipse the sun? Who were the six wives of Henry VIII? What was the first spacecraft to land on the moon? Is the moon ever actually blue? What are the names of the first astronauts who went to the moon? Who did CBS’s news commentary on July 20, 1969, the day of the first moon landing?