Radial profiles of a) pressure, b) temperature, c) gravity, and d) density for generic Earth-like exoplanets ranging from 1 (lowermost curve) to 15 M_⊕ (uppermost curve): the four compositional layers are represented by different colors, while the solid red lines in panel d) indicate discontinuities caused by pressure-induced phase transitions or step-wise compositional changes. The dashed red lines denote a reference Earth model.