PURPOSE: Bioelectrical impedance analysis (BIA) scales have gained popularly in monitoring fitness progress at home, yet their accuracy is unknown. We assessed the validity and reliability of body fat percentage (BF%) measurements from a consumer bioelectrical analysis (cBIA) scale compared to the “gold standard” of hydrostatic weighing (HW). METHODS: Forty-three [male (n=22); female (n=21)] healthy volunteers [age: 27.9±5.6y; height: 170.0±8.6cm; mass: 69.0±13.7kg; body mass index (BMI) range: 16.8-33.1] arrived at the laboratory 3h fasted after 12h without exercise and underwent measures of residual lung volume (for HW calculations), hydration status, and BF% via cBIA scale (‘Lean’ and ‘Regular’ modes) and HW. We assessed cBIA scale validity using Bland-Altman Plots (identifying Mean Biases±Limits of Agreement) and reliability using intraclass correlation coefficients (ICC). RESULTS: With HW as the validity criterion, mean BF% was 22.3±6.1% for all participants (range: 5.3-35.8%; male mean: 20.8±6.4%; female mean: 23.9±5.5%). Compared to HW, the cBIA scale in ‘Lean’ mode underestimated BF% by -5.3±9.1% for all participants (males: -7.9±6.9%; females: -2.6±8.0%) (p≤0.05). In ‘Regular’ mode, the cBIA scale agreed with HW for all participants (BF% -0.8±9.3%; p=0.27) and females (BF% 0.4±10.8%; p=0.73); however, there was a significant difference for males (BF% -2.0±7.1%; p≤0.05). The cBIA was reliable when comparing day-to-day (‘Lean’ mode: 0.5±1.0%, ICC:0.99; ‘Regular’ mode: 0.4±1.0%, ICC:0.99) and week-to-week (‘Lean’ mode: -0.4±1.4%, ICC:0.98; ‘Regular’ mode: -0.2±1.5%, ICC:0.97) BF% for all participants. CONCLUSIONS: Compared to HW, the cBIA underestimated BF% in ‘Lean’ mode, and this discrepancy was more pronounced in males. However, the cBIA scale agreed with HW when analyzing BF% in ‘Regular’ mode for all participants and females, signifying the “mode” chosen on consumer BIA devices greatly impacts validity. The cBIA was reliable when comparing day-to-day and week-to-week BF% measures for all participants, suggesting this can be a reliable at-home BF% analysis scale.