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Calcimator

Voltage Drop Calculator

Calculate voltage drop in electrical wiring based on wire gauge, length, current, and material. Ensure your circuits meet NEC recommendations.

Inputs

V
A
ft

Results

Voltage Drop

4.76 V

Voltage Drop %3.97%
Voltage at Load115.24 V
Wire Resistance0.32 Ω
Power Loss71.46 W
AssessmentMarginal (3-5%)

Voltage Drop

4.76 V

How to Use This Calculator
  1. Start by filling in the input fields below. Results update instantly as you type, so you can experiment with different values to see how they affect the outcome.
  2. Source Voltage — Electrical potential difference in volts. Accepts values from 1 V to 480 V (default: 120 V).
  3. Current — Electrical current in amperes. Accepts values from 0.1 A to 200 A (default: 15 A).
  4. Wire Length (one-way) — Total length of the wire. Accepts values from 1 ft to 2,000 ft (default: 100 ft).
  5. Wire Gauge (AWG) — Wire gauge (AWG). Choose from: 14 AWG, 12 AWG, 10 AWG, 8 AWG, 6 AWG, 4 AWG, 2 AWG. default: 12.
  6. Wire Material — enter your preferred option from the dropdown. Choose from: Copper, Aluminum. default: 0.
  7. Once all inputs are set, review your results in the Results panel. Here's what each output means:
  8. Voltage Drop — shown as a numeric value. This is the primary result of this calculator.
  9. Voltage Drop % — shown as a percentage.
  10. Voltage at Load — shown as a numeric value.
  11. Wire Resistance — shown as a numeric value.
  12. Power Loss — shown as a numeric value.
  13. Assessment — your calculated result.
  14. View the Voltage Distribution below for a visual breakdown of how the numbers relate to each other.
  15. Explore the related calculators below if you need deeper analysis or want to approach this topic from a different angle.
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Formula

Voltage Drop = Current × Wire Resistance. Wire Resistance = (Resistivity × 2 × Length) / 1000. NEC recommends ≤3% drop for branch circuits.

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