Deep mutational scanning is now used in directed evolution experiments to quantify the change in frequency of a cellular variant in a mixed population. A key concern is the extent to which the enrichment of a variant in a population corresponds to a fitness metric like relative growth rate or survival percentage. We present here analytical equations converting the enrichment of a variant to fitness metrics for plate-based selections. Using isogenic and mixed cultures we show that growth rates and survival percentages correlate for antibiotic plate-based selections. These results are important for proper interpretation of data resulting from deep sequencing.