ELECTRICAL
Wire Size Calculator
Find the right wire gauge for your circuit — voltage drop · ampacity · NEC standards
AWG
kcmil
Load & installation
A
material
temp
in cable
Recommended AWG
—
AWG
Max ampacity
—
A
Cross-section area
—
mm²
NEC 310.16 — ampacity tables
Ampacity comparison
Common AWG sizes and their ampacity
Voltage drop calculator
V
A
ft
AWG
material
Voltage drop
—
V
Voltage drop %
—
%
Wire resistance
—
Ω
Power loss
—
W
VD = 2 × L × I × R
Drop vs length
Voltage drop increases with conductor length
NEC recommendations
- < 3% — Acceptable
- 3–5% — Marginal
- > 5% — Requires larger gauge
AWG ↔ mm² conversion
AWG
mm²
AWG
—
AWG
Cross-section
—
mm²
Diameter
—
mm
Resistance (per 1000ft)
—
Ω
mm² = 0.5067 × 92^((36−AWG)/19.5)
AWG vs cross-section
Larger AWG number = smaller conductor