How do you figure out the percent of mass in all eight planets and what percent?

To determine the percent of mass for each planet in the solar system, you would divide the mass of each planet by the total mass of all the planets combined and then multiply by 100. The total mass of the eight planets (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune) is approximately 0.001 solar masses, with Jupiter containing about 70% of the total planetary mass. The individual percentages vary, with Earth at around 0.0003 solar masses, leading to roughly 0.3% of the total mass of the planets. For specific figures, you would need the exact mass values for each planet.