For laminar flow, Reynolds number is correlated with power number as (where K, a constant which depends on the container geometry and shape of stirrer; Re_{i} is Reynolds number for agitator; D_{i}, stirrer diameter and N, stirrer speed)

For turbulent flow, Reynolds number is correlated with power number as (where K, a constant which depends on the container geometry and shape of stirrer; Re_{i}, is Reynolds number for agitator; D_{i}, stirrer diameter and N, stirrer speed)