We analyzed 5 years of Texas statewide data on high school size and college readiness in English Language Arts, math, and in both subjects for White students. Using Greeney and Slate's (2012) criteria, large-size high schools had over 1,500 students, medium-size high schools had 401 to 1,500 students, and small-size high schools had enrollments under 400. White students enrolled in large-size high schools had statistically significantly higher college readiness rates in English Language Arts, math, and in both subjects than White students enrolled in medium-size and small-size high schools for each of the 5 years examined in this study. Effect sizes were moderate for all 3 areas and for all 5 years. As such, support was provided for the economies of scale theoretical framework. Implications for policymakers and recommendations for research are present.