Objective: This paper evaluated harness sizing schemes and anthropometric criteria for harness design applications. Background: Updated harness sizing systems are needed to accommodate diverse populations in the current workforce. Method: Three-dimensional torso scan data and human-harness interfaces from 108 women and 108 men were digitally captured. Abounding box approach was employed to quantify the effect of torso shape and size on fall harness fit. Results: Alogistic regression model with eight equations was developed and tested to classify more than 96% of participants to the best-fitting size. Conclusion: Study outcomes suggested an alternative system of two sizes for women and three sizes for men over the current four-size unisex system. In addition, thigh strap angle and back D ring location could be utilized along with current harness static fit test criteria to further enhance postfall harness fit predictions. Application: This research could help reduce the risk of worker injury resulting from poor fit, improper size selection, or failure to don the harness properly.