The “Timed-Up-and-Go” test (TUG) is a standard assessment tool for functional mobility as it assesses several functional components, including balance, gait, and lower-extremity strength. It has good reliability and validity and is cost-effective and safe, making it an ideal screening tool for falls in various populations, such as older adults or various conditions. However, TUG interpretation relies on comparisons against local normative reference values (NRV), which few studies established for the Asian or younger population. Hence, this study aims to: (1) establish the normative reference values NRV for the population aged 21 to 85 years; (2) determine demographic and anthropometric variables that influence the TUG results; and (3) establish the regression equation of the TUG. A prospective, convenience sampling cross-sectional study recruited subjects aged 21–85 from the community to complete two TUG trials in various parts of Singapore. Variables collected include gender, age, height (meters, m), weight (kilograms, kg), and hand grip strength (HGS) (kg). The intraclass correlation coefficient (ICC) and 95% confidence interval (95% CI) determined test-retest, intra- and inter-rater reliabilities. TUG and variables were analyzed with descriptive statistics and multiple linear regression.p< 0.05 was accepted as statistical significance. Further, 838 subjects (542 females, 296 males) completed the data collection. The mean TUG time was 9.16 s (95% CI 9.01–9.3). Slower TUG was observed with advanced age and female gender. Multiple linear regression analysis demonstrated that age, height, and weight were the best variables to predict TUG scores. The regression formula presented as: TUG (second) = 9.11 + 0.063 (Age, years)—3.19 (Height, meters) + 0.026 (Weight, Kilograms) (R2= 0.374,p< 0.001). This study provided the TUG NRV and regression formula for healthy Asian adults aged 21 to 85. The information may provide a quick reference for the physical function to interpret assessment findings and guide decision-making in various health and healthcare settings.