The distance from the Earth's crust to its core is approximately 2,900 kilometers (1,800 miles).

Here's a breakdown of the Earth's layers and their approximate thicknesses:

* Crust: 5 to 70 kilometers (3 to 43 miles) thick

* Mantle: 2,900 kilometers (1,800 miles) thick

* Outer Core: 2,200 kilometers (1,400 miles) thick

* Inner Core: 1,220 kilometers (760 miles) thick

So, from the surface of the Earth (crust) to the very center (inner core) is about 6,371 kilometers (3,959 miles).