McNally (McNally, 1987)

UCS = 185165 e^(–0.037Dt)

where

185165 is in psi.

-0.037 is in μs/ft.

The McNally equation is calibrated against several hundred sandstones core samples from 24 wells in coal mines in Australia. The samples were mostly well-cemented fine to medium-grained sandstones. The McNally equation is most applicable to consolidated sandstones with acoustic transit time ranging between 65 and 120 microseconds per foot. This is selected as the default equation for sandstone.