The depth of the Earth's crust compared to the rest of the Earth is comparable to the thickness of the skin of an apple compared to the entire apple.

Here's a breakdown:

* Earth's crust: Ranges from about 3-50 km (2-30 miles) thick, depending on whether it's oceanic or continental crust.

* Earth's radius: About 6,371 km (3,959 miles).

This means the crust is only about 0.5% of the Earth's total radius.

The analogy of the apple skin is a good visual representation. The thin outer layer of the skin is like the crust, while the rest of the apple represents the mantle and core, which are much thicker and deeper.