Mars vs Earth
Using mean diameters, Mars is 6,779 km across and Earth is 12,742 km. Mars is about 53.2% as wide. These are rounded mean diameters, rather than equatorial measurements.
| Object | Real size | Source | |
|---|---|---|---|
| MarsDiameter, averageMean radius 3,389.50 km × 2 = 6,779 km. The circular drawing uses the mean, not equatorial, diameter. | 6,779 km4,212 mi | Mean diameter derived from mean radius; not equatorial diameter. Measurement recordSource checked | |
| EarthDiameter, averageMean radius 6,371.0084 km × 2, rounded to a mean diameter of 12,742 km. The circular drawing uses the mean, not equatorial, diameter. | 12,742 km7,918 mi | Mean diameter derived from mean radius; not equatorial diameter. Measurement recordSource checked |
What measurements does this comparison use?
The reference values used here are 6,779 km for Mars (Diameter, average) and 12,742 km for Earth (Diameter, average). The table links to background sources; natural objects and manufactured variants can differ from these reference values.
How should I read the drawing?
Earth spans about 1.9× as much as Mars across the longest side of each drawing. This is a linear scale comparison, not a comparison of mass or volume. For maps, the table reports area; doubling a map’s width and height multiplies its area by four.
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