Calculate Current from Voltage Drop

Formulas

For AC Single-phase and DC:

$$ I = \frac{V_{drop} \times A}{2 \times L \times \rho} $$

For Three-phase:

$$ I = \frac{V_{drop} \times A}{\sqrt{3} \times L \times \rho} $$

Definitions

• Current (I): The flow of electric charge, measured in amperes (A).
• Resistivity (ρ): A material property that indicates how much the material resists the flow of electric current, measured in ohm-meters (Ω·m).
• Cross-Sectional Area (A): The area of the wire's cross-section, measured in square meters (m²).
• Voltage Drop (V_drop): The reduction in voltage in an electrical circuit between the source and load.
• Length (L): The length of the wire, measured in meters (m) or feet (ft).

Conversion Table