Choose copper wire weight, diameter, length or density, then enter the requested quantities. The model assumes a bare solid round conductor; supported units are converted consistently.

Bare solid round conductor only; excludes insulation and gaps between strands.

559 lb/ft³ is a rounded copper estimate; use a material specification when known.

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

Choose the value to solve for. The calculator uses the formula above for weight and rearranges it for diameter, length or density.

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 ≈ 1.9905 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 separately rounded room-temperature estimates, not exact unit equivalents. The default 559 lb/ft³ converts to approximately 8954.35 kg/m³ or 8.95435 g/cm³; unit changes preserve your entered density. 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.