What percentage of the earth's core is iron?
The core of the Earth is thought to consist of roughly 80% iron.
We do not know exactly because there is no way to get to it it find out. We know the outer core composed mainly of a nickel-iron alloy. We believe that the composition of Iron meteorites must be similar to that of the outer core and the the alloy in these ranges from 5% to 62% nickel from meteorite to meteorite with an average of 5% nickel leaving 95% Iron.