⚡ Electrical Cable Size Calculator
Accurate cable sizing for safe & efficient wiring installations
Determine the appropriate electrical cable size based on current load, voltage drop limits, cable length, and installation conditions.
Input Parameters
Calculation Results
Enter your parameters
Fill in the form and click “Calculate” to get recommended cable size
Recommended Cable Size
AWG: –
Voltage Drop
Within limits
Current Carrying Capacity
Safe for your load
Safety Notes
- Always consult local electrical codes
- Consider derating factors for multiple cables
- Account for future load increases
About Cable Sizing
Why Proper Cable Sizing Matters
- Prevents overheating and potential fire hazards
- Ensures efficient power delivery with minimal voltage drop
- Complies with electrical codes and standards
- Reduces energy losses and saves costs
Key Factors in Cable Sizing
Current Carrying Capacity
The cable must safely carry the full load current without overheating.
Voltage Drop
The voltage at the load should be within acceptable limits (typically 3-5% drop).
Installation Conditions
Ambient temperature, grouping with other cables, and installation method affect cable rating.
Quick Reference Tables
Copper Cable Current Ratings (Amps)
| Size (mm²) | In Conduit | Free Air |
|---|---|---|
| 1.5 | 15 | 20 |
| 2.5 | 21 | 27 |
| 4 | 28 | 37 |
| 6 | 36 | 46 |
| 10 | 50 | 63 |
* Ratings based on 30°C ambient temperature
Recommended Voltage Drop Limits
| Application | Max Drop |
|---|---|
| Lighting Circuits | 3% |
| Power Outlets | 5% |
| Motors at Startup | 15% |
| Motors Running | 5% |
* Check local regulations for specific requirements