* Continental crust: This is the thicker crust, typically around 40 km thick. It's made up of less dense, lighter rocks like granite.

* Oceanic crust: This is the thinner crust, typically around 8 km thick. It's made up of denser, heavier rocks like basalt.

So, the thickness of the Earth's crust is approximately 40 km for continental crust and 8 km for oceanic crust.