Here's a breakdown:

* Crust: The outermost layer of Earth, composed of relatively light, solid rock. It's about 3-5 miles thick under the oceans (oceanic crust) and 25 miles thick under the continents (continental crust).

* Mantle: The layer beneath the crust, extending to a depth of about 1800 miles. It's mostly solid rock, but it behaves like a very viscous fluid over long periods.

Therefore, the mantle is significantly thicker than the crust.