What is Calculation of electrical cable size?

CABLE.SIZING.FORMULA::2*L*I/(K*Vd)...............FOR.SINGLE.PHASE I……..LOAD.CURRENT.=160….AMPS L…….LENGTH.OF.THE.CABLE.= 200 METERS K……CONDUCTIVITY.OF.COPPER.=.58,AND.CONDUCTIVITY.OF.ALUMINUM.=36 Vd:- VOLTAGE DROP3% OF230 VOLTS=6.9 VOLT AND FOR3PH.3% OF400VOLT=12 VOLTS APPLY.THE.FORMULA:- AREA(mm2) =2 * L * I/(K * Vd) =2 *200*160/(58*6.9) =159.92 mm2 required(FOR SINGLE PHASE) AREA(mm2) =1.732*L*I/(K*Vd) =1.732*200*160/(58*12) =79.6 mm2 required(FOR THREE PHASE)

you should use relations and formula  in standards and be aware of voltage drop and heat effect. each cable has its own detaile and Specifications. 

it is a right answer hazem

We can calculate the size of the cable we need , using this formula : S= I / D S : Section of the cable. I : Intensity , which is the current in Ampere. D : Density, which is theoretically equal to5 and for safety we consider it3.