It took roughly 4.5 billion years for the planets in our solar system to form. This timeframe is a rough estimate, as the process was not a smooth, linear progression.

Here's a breakdown of the key stages:

* First 100,000 years: The solar nebula, a massive cloud of gas and dust, began to collapse under its own gravity.

* Next few million years: The central region of the collapsing nebula formed the Sun.

* Next tens of millions of years: Dust and gas particles started clumping together, forming planetesimals – small, rocky bodies. These planetesimals continued to collide and grow, eventually forming the planets.

* Final stages: Over billions of years, the planets migrated, interacted with each other, and settled into their current orbits.

It's important to note that the planets were not formed simultaneously. Some planets, like Mercury, formed faster than others, like Jupiter.

Therefore, the formation of our solar system was a complex and dynamic process that spanned over billions of years.