Methods and apparatus for measuring pitch-walking are disclosed. Embodiments include forming parallel, spaced mandrels in test sites on a substrate; performing two SIT processes, forming first-fourth fins in the substrate for each mandrel; designating spaces between first and second and between third and fourth fins as β, between first and fourth fins of adjacent mandrels as α, and between second and third fins as γ in each test site; applying a first lithomask over fins at a first test site selecting spaces designated as one of α, β, or γ and the adjacent fins; applying a second lithomask over fins at a second test site selecting second spaces, designated as a different one of α, β, or γ and the adjacent fins; measuring the selected first and second spaces; determining differences between the measured first and second spaces; and adjusting processes for forming fins based on the differences.