Cutaneous functional units (CFUs) are fields of skin that functionally contribute to range of motion (ROM) at an associated joint. When replaced with scar tissue, the skin is less extensible and may result in loss of movement at the joint. Consideration of the amount of CFU affected by burn injury is increasingly being used to predict the development of burn scar contracture (BSC) in burn survivors. Previous work established that, in adults, burn rehabilitation time per CFU was the greatest predictor of preventing BSC. Our study aimed to examine the direct relationship between percent involvement of CFU and ROM achieved in children with BSC who received 6 months of rehabilitation therapy services. ROM was measured at baseline and throughout the study period using traditional methods of goniometry as well as three-dimensional motion capture during the performance of functional tasks. Burn extent and distribution were mapped using an electronic diagram to calculate the percentage of CFU affected by scarring or skin grafts. Pearson’s correlations and multivariate linear regression analyses were performed to determine associations between variables. Results showed that percent CFU involvement was negatively correlated with maximal goniometric and functional shoulder ROM achieved. That is, the amount of a given CFU scarred was predictive of less ROM achieved in the associated area. Percentage of CFU involved did not significantly correlate with baseline shoulder ROM, suggesting that other factors may be associated with initial limitations in ROM. Evaluation of the percentage of CFU scarred is useful for predicting shoulder ROM recovery with rehabilitation and may be used to help guide clinical decision making and allocation of time and resource for therapy services.