Calculate copper wire weight, diameter, length or density from any 3 inputs and convert between inch, cm, m, ft, kg and lb units as needed.
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Copper Wire Weight Formula
The calculator uses the volume of a round wire multiplied by density. In its base calculation, diameter is in inches, length is in feet, density is in pounds per cubic foot, and weight is in pounds.
W = (pi*(D/2)^2*L*rho)/144
- W = copper wire weight, in pounds
- D = wire diameter, in inches
- L = wire length, in feet
- rho = density, in pounds per cubic foot
- pi = 3.14159
- 144 = conversion factor from square inches to square feet
If you leave weight blank, the calculator uses the formula above to find the wire weight. If you leave another field blank, it rearranges the same formula.
D = 2*sqrt((144*W)/(pi*rho*L))
L = (144*W)/(pi*(D/2)^2*rho)
rho = (144*W)/(pi*(D/2)^2*L)
- Find diameter: enter weight, length, and density.
- Find length: enter weight, diameter, and density.
- Find density: enter weight, diameter, and length.
- Find weight: enter diameter, length, and density.
Copper Density and Common Wire Weights
Pure copper density is commonly rounded, so small differences in density values can slightly change the result.
| Copper density unit | Typical value | Use in calculator |
|---|---|---|
| lb/ft³ | 559 | Default value |
| kg/m³ | 8950 | Metric density input |
| g/cm³ | 8.96 | Small-scale material density input |
The table below gives approximate bare solid copper weights using 559 lb/ft³. Insulation, jacketing, plating, and stranding can change the actual finished cable weight.
| AWG size | Diameter, in | Approx. copper weight per 1,000 ft |
|---|---|---|
| 14 AWG | 0.0641 | 12.5 lb |
| 12 AWG | 0.0808 | 19.9 lb |
| 10 AWG | 0.1019 | 31.7 lb |
| 8 AWG | 0.1285 | 50.3 lb |
| 6 AWG | 0.1620 | 80.0 lb |
| 4 AWG | 0.2043 | 127.3 lb |
Example Calculations
Example 1: Find copper wire weight
You have a copper wire with a diameter of 0.0808 in, a length of 100 ft, and a density of 559 lb/ft³.
W = (pi*(0.0808/2)^2*100*559)/144
W = 1.991 lb
The copper wire weighs about 1.99 lb.
Example 2: Find wire length from weight
You have 5 lb of copper wire with a diameter of 0.1019 in. Use 559 lb/ft³ for copper density.
L = (144*5)/(pi*(0.1019/2)^2*559)
L = 157.9 ft
The wire length is about 157.9 ft.
FAQ
Does this calculate the weight of insulated copper wire?
No. The formula calculates the copper conductor weight from diameter, length, and density. If the wire has insulation, jacketing, shielding, or other materials, the total cable weight will be higher than the copper-only result.
What density should you use for copper?
For most estimates, use 559 lb/ft³, 8950 kg/m³, or 8.96 g/cm³. These are standard rounded values for copper. If you have a specific copper alloy or material specification, use the density from that specification.
Why is there a 144 in the formula?
Diameter is entered in inches, so the circular cross-sectional area is in square inches. Length is in feet and density is in pounds per cubic foot. Dividing by 144 converts square inches to square feet so the volume matches the density unit.
