Calculateur de Calibre de Fil
Calculateur gratuit de calibre de fil. Entrez AWG ou mm², longueur du fil, courant et matériau pour calculer la résistance, la chute de tension et l'ampacité.
Calculez la résistance du fil, la chute de tension et l'ampacité pour les tailles AWG/mm².
Wire gauge determines electrical conductor diameter or cross-section. This calculator converts between American Wire Gauge (AWG) and metric millimetres squared (mm²), calculating resistance, voltage drop, power loss, and ampacity.
What is Wire Gauge?
The AWG (American Wire Gauge) system and metric mm² both measure conductor size. Lower AWG numbers indicate thicker wires. Selection affects circuit safety, efficiency, and compliance with electrical codes.
Key Parameters
- Size Unit: AWG (North American) or mm² (metric international standard)
- Wire Size: Conductor diameter or cross-section
- Wire Length: Distance conductor spans (one-way)
- Current: Steady-state electrical current in amperes
- Material: Copper (lower resistance) or aluminum (lightweight)
- Frequency: DC (direct) or AC at 50/60 Hz
Physics
Resistance: R = ρL/A where ρ is resistivity, L is length, A is cross-section.
Voltage drop: V = IR
Power loss: P = I²R (dominant heating mechanism)
AC adds ~5% penalty due to skin effect — current concentrates on conductor surface at high frequencies.
How to Use
- Select AWG or mm² units
- Enter wire gauge or cross-section
- Specify one-way conductor length
- Enter continuous current in amperes
- Choose material (copper/aluminum)
- Select frequency (DC/AC 50/60 Hz)
- Review calculated results
Example
For a 12 AWG copper conductor carrying 15 A over 25 m at 60 Hz AC:
- Resistance: ~0.207 Ω
- Voltage drop: ~3.1 V
- Power loss: ~2.3 W
- Safe ampacity: >20 A ✓
FAQ
Q: Difference between AWG and mm²? A: AWG (American) and mm² (metric) measure the same thing — cross-sectional area — using different scales. Both determine conductor properties.
Q: Why does aluminum require larger sizes? A: Aluminum has ~60% higher resistivity than copper. For equivalent ampacity, use 1.5–2× cross-section.
Q: What is skin effect? A: At high AC frequencies, current crowds toward the conductor surface, increasing effective resistance 5–15%.
Q: How do I avoid voltage drop problems? A: Keep voltage drop ≤3% (branch circuits) or ≤5% (overall). Larger wire reduces both voltage drop and power loss.
Q: Can I use one wire for return? A: In AC systems, return current uses a separate conductor (neutral/return/ground). Measure length one-way; calculator accounts for this.