Few days ago, we received an inquiry which asks that how many meters of copper wire is there in one roll.

Theoretically, it can be caculated by using formula: W(g)=π*d(mm)² /4*P（g/cm³）*100

W represents 1 meter’s wire’s weitht; D represents wire’s diameter; P represents density of conductor. 

First of all, we need to confirm several data--the size of roll, wire’s diameters, the conductor’s material(to confirm the density). The copper’s density is 8.9g/cm3; the aluminum’s density is 2.7g/cm3.

Take 0.404mm copper wire as an example. Shanghai ZOTO usaually use PT25 roll for this diameter. Normally, the wire’s weith should be 20-30 Kg in one roll. Therefore by caculating one meter wire’s weitht, then we can caculate the length if the wire weights 20-30 Kg. You should pay particular attention to the unit conversions.

Therefore，W(g)=3.14*0.0404(cm)² /4*8.9(g/cm³)*100=1.14g;

Length A in one roll(meter)=20000(g)/1.14(g)=17543.86(m)

Length B in one roll(meter)=30000(g)/1.14(g)=26315.79(m)

Although our company- Shanghai Zhongtuo Magnet Wire Co., Ltd. mainly produce enameled wire, but we still can idealize to caculate by using these formula (ignoring the coating layer).