220 Volt Wire Size Calculator
Calculate the proper wire size for 220V electrical circuits with voltage drop analysis
Calculate 220V Wire Size
Maximum current the wire will carry
Distance from power source to load
Typical range: 3-5% for branch circuits
Material affects electrical resistivity
Wire operating temperature affects resistance (reference: 20°C)
Wire Size Results
Formula used: A = 2 × I × ρ × L / (V × %drop)
Parameters: Current: 0.00A, Distance: 0.00m
Material: copper (ρ = 1.88 µΩ⋅cm at 50°C)
Safety Analysis
Example Calculation
Water Heater Installation
Load: 20 Amp electric water heater
Voltage: 220V
Distance: 50 meters from panel
Material: Copper wire
Allowable voltage drop: 3%
Calculation
A = 2 × 20A × 1.68×10⁻⁸ Ω⋅m × 50m / (220V × 0.03)
A = 33.6×10⁻⁶ / 6.6 = 5.09×10⁻⁶ m²
Required wire size: 5.09 mm²
Recommended: 6 mm² (10 AWG) copper wire
Common Wire Sizes
Safety Tips
Always consult a qualified electrician
Check local electrical codes
Consider ambient temperature
Use proper circuit protection
Never exceed wire ampacity ratings
Understanding 220V Wire Size Calculations
Why Wire Size Matters
Proper wire sizing ensures safe operation, prevents overheating, and minimizes voltage drop. Undersized wires can cause fires, while oversized wires waste money and installation space.
Key Factors
- •Current Load: Maximum current the wire will carry
- •Distance: Length affects voltage drop
- •Material: Copper vs aluminum resistivity
- •Temperature: Heat increases resistance
Wire Size Formula
A = 2 × I × ρ × L / (V × %drop)
- A: Cross-sectional area (m²)
- I: Current (A)
- ρ: Resistivity (Ω⋅m)
- L: One-way distance (m)
- V: Voltage (220V)
- %drop: Allowable voltage drop (%)
Note: Factor of 2 accounts for round-trip current path
Voltage Drop Guidelines
Branch Circuits
3% maximum voltage drop
Feeder Circuits
3% maximum voltage drop
Total System
5% maximum voltage drop