How many layers are in the earth?

Answer 1

There are 3 basic layers to the Earth, the crust, the mantle and the inner core. I'm sure there are more sub layers though.

There is also the outer core, which surrounds the inner core. Hence each one's names. 4 main layers.

Answer 2

Here are the layers of the earth with depths in Km.

1. 0- 40 Crust
2. 40- 400 Upper mantle
3. 400- 650 Transition region
4. 650-2700 Lower mantle
5. 2700-2890 D'' layer
6. 2890-5150 Outer core
7. 5150-6378 Inner core