Mars is much smaller than Earth: it’s a bit over half Earth’s diameter, with only about a quarter to a third of Earth’s surface area and roughly a tenth of its mass.

Quick Scoop

  • Mars’ diameter is about 6,790–6,800 km; Earth’s is about 12,700–12,800 km, so Mars is roughly 53% as wide as Earth.
  • Mars has about 15% of Earth’s volume and about 10–11% of Earth’s mass.
  • Mars’ total surface area is roughly 28–38% of Earth’s, similar to the area of all Earth’s dry land put together.
  • Gravity on Mars is only about 37–38% of Earth’s, so you’d weigh a bit more than one‑third of your Earth weight there.

Size and gravity at a glance

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Property Earth Mars Mars vs Earth
Diameter ≈ 12,742 km ≈ 6,792 km ≈ 53% of Earth
Radius (equatorial) ≈ 6,378 km ≈ 3,396 km ≈ 53% of Earth
Surface area ≈ 510 million km² ≈ 145 million km² ≈ 28–38% of Earth, similar to Earth’s land area
Volume ≈ 1.08 × 10¹² km³ ≈ 1.63 × 10¹¹ km³ ≈ 15% of Earth
Mass ≈ 5.97 × 10²⁴ kg ≈ 6.4 × 10²³ kg ≈ 10–11% of Earth
Surface gravity 1 g (9.8 m/s²) ≈ 0.37–0.38 g ≈ 37–38% of Earth

A quick way to picture it

If Earth were the size of a basketball , Mars would be more like a small soccer ball or a large orange sitting next to it. You’d also feel dramatically lighter on that smaller world, bouncing around at just over one‑third of your Earth weight.

TL;DR: Mars is just over half as wide as Earth, has land area similar to all Earth’s continents combined, and its gravity is only about 38% of Earth’s.

Information gathered from public forums or data available on the internet and portrayed here.