Cable Size Estimator
Minimum standard cable cross-section to keep voltage drop within your limit.
Inputs
V
A
m
%
Results
- Recommended size
- 10 mm²
- Minimum calculated area
- 6.38 mm²
- Voltage drop at that size
- 1.91 %
⚠ Also check current-carrying capacity, installation method and protective device rating per your local wiring code.
Formula
A min = k × I × L × ρ ÷ (V × max drop %)
k = 2 (single/DC) or √3 (three-phase); pick next standard size
Assumptions & limits
- Voltage-drop sizing only — an estimator, not a code-compliant design.
- Conductor resistivity at 20 °C.
Worked example
2 × 32 × 40 × 0.0172 ÷ 6.9 = 6.38 mm² → 10 mm².