Free Cable Sizing Calculator

Estimate the minimum cable cross-sectional area based on current capacity requirements.

A
A/mm^2

Minimum Conductor Area

10.0 mm^2

Minimum Conductor Area vs Design Current (I)

Cable Sizing by Current Density

The cable must carry the required current without exceeding safe temperature limits.

Simplified Method

A = I / J

where A is the conductor cross-sectional area, I is the design current, and J is the allowable current density. Typical values: enclosed cables 3-4 A/mm^2, open-air cables 5-6 A/mm^2. Always verify against manufacturer ampacity tables and installation derating factors.

Example Calculation

40 A load with 4 A/mm^2 allowable current density.

  1. 01A = 40 / 4 = 10 mm^2
  2. 02Select the next standard size: 10 mm^2 or 16 mm^2 depending on available sizes.
  3. 03Also verify voltage drop is within limits for the cable run length.

Frequently Asked Questions

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