Calculate safe conductor ampacity with correction factors included. Compare copper, aluminum, insulation, and installation methods. Visualize results, download reports, and apply design values confidently.
Enter the conductor details, derating conditions, and optional design load. Results will appear above this form after calculation.
The chart compares corrected ampacity across common conductor sizes for the currently selected material and installation conditions.
A is conductor area in mm², Jbase is the selected base current density, and each factor adjusts the result for temperature, installation, grouping, or burial conditions.
Sample values below assume copper, XLPE insulation, cable tray installation, 40°C ambient, 3 loaded cores, 2 grouped circuits, and 10% safety margin.
| Area (mm²) | Base Density (A/mm²) | Corrected Ampacity (A) | Recommended Working Current (A) | Design Comment |
|---|---|---|---|---|
| 16 | 5.8 | 69.79 | 62.81 | Suitable for moderate feeder loads. |
| 25 | 5.8 | 109.04 | 98.14 | Good for heavier branch circuits. |
| 35 | 5.8 | 152.66 | 137.39 | Common industrial distribution choice. |
| 50 | 5.8 | 218.08 | 196.27 | Useful for larger motors and panels. |
Current capacity is the maximum continuous current a conductor can carry without exceeding its safe operating temperature under stated installation conditions.
Higher surrounding temperature reduces heat dissipation. That lowers safe ampacity and requires a temperature derating factor before selecting cable size.
Copper has lower resistance and generally carries more current for the same cross-sectional area. Aluminum needs larger sizes for comparable performance.
When several circuits are close together, each cable runs hotter. The grouping factor reduces the calculated ampacity to reflect that shared heating effect.
No. Recommended working current subtracts the selected safety margin from corrected ampacity, giving a more conservative value for practical design use.
Length helps estimate conductor resistance and voltage drop. A cable may pass ampacity checks but still fail voltage drop limits on long runs.
No. It is a design-support estimate. Final selections should always be checked against your governing electrical code, manufacturer data, and project conditions.
Adjust it for buried cables when site data differs from standard soil assumptions. Poorer heat transfer lowers underground ampacity.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.