BIA is hydration-dependent. Learn what affects your reading and how to control it. Your data stays in your browser.
See how hydration changes affect your BIA reading. This is a simulation, not a measurement.
This simulator demonstrates how bioelectrical impedance analysis (BIA) estimates body composition by sending a harmless electrical current through your body. Because water conducts electricity and fat does not, the device measures impedance (resistance) to estimate total body water, then derives lean mass and body fat. The simulation applies two key modifiers: hydration level (more water = lower impedance = lower BF% reading) and device type (consumer foot-only scales have higher error than professional 8-electrode units). The result is an educational estimate, not a medical measurement. Use the consistency checklist to understand why your real-world BIA readings fluctuate day-to-day.
Tip: A 2% change in total body water can swing BIA readings by 3-5%. Always measure under consistent conditions — same time, same hydration, same menstrual phase.
Print this and put it on your bathroom mirror. Follow it every time you measure.
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Cross-check your BIA reading with other methods.
See if your BIA reading aligns with other metrics.
A hydration-independent alternative to BIA.
BIA measures electrical impedance, which is highly sensitive to hydration. A 2% change in total body water can swing readings by 3-5%.
First thing in the morning, after using the bathroom, before eating or drinking. This minimizes hydration variance.
Consumer foot-only scales have ±5-8% error. Professional 8-electrode devices (hand + foot) achieve ±2-3%. Use BIA for trends, not absolutes.
No. This simulator demonstrates hydration effects for educational purposes. Real devices use proprietary algorithms that vary by manufacturer.