- Mercury

- Diameter: 4,879 km (3,032 mi)

- Volume: 6.083 × 10¹⁰ km³ (1.453 × 10¹¹ mi³)

- Mass: 3.301 × 10²³ kg (7.276 × 10²³ lb)

- Venus

- Diameter: 12,104 km (7,520 mi)

- Volume: 9.38 × 10¹¹ km³ (2.24 × 10¹² mi³)

- Mass: 4.869 × 10²⁴ kg (1.073 × 10²⁵ lb)

- Earth

- Diameter: 12,756 km (7,926 mi)

- Volume: 1.083 × 10¹² km³ (2.599 × 10¹² mi³)

- Mass: 5.972 × 10²⁴ kg (1.316 × 10²⁵ lb)

- Mars

- Diameter: 6,792 km (4,220 mi)

- Volume: 1.631 × 10¹¹ km³ (3.92 × 10¹¹ mi³)

- Mass: 6.419 × 10²³ kg (1.415 × 10²⁴ lb)

As can be seen from the table above, the relative sizes of the inner planets are as follows:

1. Earth

2. Venus

3. Mars

4. Mercury

It is also evident from the table that the inner planets can be divided into two groups based on their size:

- Terrestrial planets (Mercury, Venus, Earth, and Mars)

- These planets are composed primarily of rock and metal.

- Jovian planets (Jupiter, Saturn, Uranus, and Neptune)

- These planets are composed primarily of gas and liquid.