Background: To evaluate the accuracy of arm circumference (AC) compared with other anthropometric and functional indicators as a predictor of sarcopenia risk in community-dwelling older adults. Methods: This was a cross-sectional, analytical, population-based study derived from a household survey involving individuals aged 60 years or older. Measurements of AC, calf circumference (CC), and variables related to muscle strength, muscle mass, and functional performance were collected, including the Timed Up and Go test, sit-to-stand test, and gait speed. Results: The sample comprised 708 older adults, predominantly female (64.7%), aged between 60 and 94 years. The prevalence of sarcopenia was 14.7%, with 4.9% classified as severe. AC showed a negative association with sarcopenia (β=–0.01, 95% confidence interval [CI] 0.75–0.92, p<0.01) and reduced the odds of sarcopenia by 17% for each additional centimeter (odds ratio=0.83, 95% CI 0.75–0.92). The comparison of the areas under the receiver operating characteristic curves (AUC) indicated similar performance between AC and CC (z=0.24, p=0.81). The diagnostic accuracy of AC was slightly higher than that of CC in male (27.1% vs. 26.6%) and female (43.0% vs. 37.6%). Conclusion Both AC and CC demonstrated high discriminative capacity for sarcopenia, with cutoff points that balanced sensitivity and specificity. AC stands out as a viable, simple, and effective alternative for sarcopenia screening in community-dwelling older adults.