Cable Power Loss Calculator, Formula, Calculation

Cable power loss calculator:

Choose the type of cable, then enter the number of core, current flow, length of the cable and the cross-section. Then press the button to calculate the total power loss.

By default, we have added 35 sqmm cables, by pressing the calculate button you can get the loss in kW. Also, you can change the value.

Choose Reading or unit:  
Enter Cable Size: Sqmm
Enter Current Flow: Amps
Enter length M
Enter Number of Core:  
Power Loss: kW

Cable Power Loss Calculation:

Cable power loss P(loss-kW) in kilowatts is equal to 1000 times of the length of the conductor l(M), the square of current I(A) in amps, the resistivity of the conductor ρ(Ω-m) in ohm-meter divided by the cross-section A(sqmm) of the conductor in (sqmm). The cable power loss calculation formula can be written as,

Learn More:   kW to Cable Size Chart & Electrical Cable Size Chart Amps

P(loss-kW) = 1000 x I(A)2 x ρ(Ω-m) x l(M) / A(sqmm)

The above formula is suitable for single-core power loss calculation.

In case, if you have multi-core, with the same current flow, you can multiple the number of the core with the above formula. Hence,

Power loss in Multicore cable is equal to the product of a number of core N and the loss in a single core.

P(loss-kW) = N x 1000 x I(A)2 x ρ(Ω-m) x l(M) / A(sqmm)

Silver has 1.59×10−8 ohm-meter & copper has 1.68×10−8 for aluminium 2.82×10−8 ohm-meter. Look, the resistivity will be varied based on the conductor.


Let we calculate the power loss of the 3 core, 35 Sqmm aluminium cable for the length of 1000 meter @ 50 Amps current flow.

P(loss-kW) = 3 x 1000 x 502 x 2.82 × 10−8 x 1000 / 35

= 604285714.3 × 10−8

Power loss = 6.04 kW


Please enter your comment!
Please enter your name here