How big is Jupiter compared to Mars?
20.6×wider than Mars
Jupiter is 20.6× wider than Mars — 139,820 km across against Mars’s 6,779 km. By volume, about 8,774 Marses would fit inside Jupiter. Jupiter has 2,970× Mars’s mass.
▶ See Jupiter and Mars in 3D
Side by side
Diameter
Jupiter 139,820 km · Mars 6,779 km
Width ratio
Jupiter is 20.6× wider
Volume
8,774 Marses fit inside Jupiter
Mass
Jupiter is 2,970× Mars
Gravity (Jupiter · Mars)
24.8 m/s² · 3.7 m/s²
Distance from Sun
5.2 AU · 1.52 AU
You could fit roughly 8,700 Marses inside Jupiter and still have room to spare.
What sets them apart
This is the solar system’s size gap at its most extreme: a giant against a small rocky world. Jupiter is more than twenty times wider than Mars and thousands of times its mass. Set on Jupiter’s cloud tops, Mars would be smaller, relative to the planet, than the Great Red Spot storm.
Ratios are easy to nod along to and impossible to picture. In the interactive view, switch to True scale to see Jupiter and Mars at their honest relative sizes.
Keep going
✓ Facts verified July 2026
Every figure on this page is a real, rounded value checked against primary sources. Found something out of date? See how we keep it accurate.