Calculate Cable Size ((full)) May 2026

You need at least 7.3 mm² . The nearest standard size is 10 mm² (since 6 mm² would be too small). Step 4: Adjust for Temperature and Grouping The formula above assumes ideal conditions. If cables run through hot attics or are bundled together, use these derating factors (from NEC/CEC tables):

Now calculate cable size for , not 5A. Quick Reference: Common Cable Sizes & Current Ratings (Copper, 30°C) Use this as a starting point only—always verify with local codes. calculate cable size

[ \textMin. Cross Section (mm²) = \frac2 \times \rho \times I \times LV_d ] You need at least 7

But don't worry. Calculating the correct cable size is straightforward once you understand the four key factors: calculate cable size