This paper presents a model to estimate the rate of capacity utilization (CU) in the manufacturing sector by state. Consistent measures of state-level CU rates have been unavailable since 1982. The lack of a capacity measure has hindered regional studies of capital formation, long-run output growth, and productivity growth. Our model employs a neoclassical approach to estimate CU. We estimate a model to determine the optimal level of production and compare it with the actual level in order to define our CU index. Our results show that states in the West North Central, South Atlantic, and Pacific census divisions tend to have a CU index consistently above the nation's average. On the other hand, states in the East North Central and West South Central census divisions tend to have a CU index below the nation's average.