Copper Wire Weight Chart: Pounds per Foot, Spool Estimates

Bare copper wire weight varies by wire size. The weight depends on the wire’s size, material, and construction, not simply its length. Use this chart for common round copper-wire sizes, then adjust your calculation for stranded wire, insulation, or shaped jewelry wire.

AWG Size	Bare Diameter (in)	Weight (lb/ft)	Weight (lb/1,000 ft)	Length (ft/lb)
4/0	0.4600	—	640.5	—
3/0	0.4096	—	507.9	—
2/0	0.3648	—	402.8	—
1/0	0.3249	—	319.4	—
1	0.2893	—	253.3	—
2	0.2576	—	200.9	—
4	0.2043	—	126.3	—
6	0.1620	—	79.46	—
8	0.1285	—	49.97	—
10	0.1019	—	31.43	31.82
12	0.0808	—	19.77	50.59
14	0.0641	—	12.43	80.44
16	0.0508	—	7.818	127.9
18	0.0403	—	4.917	203.4
20	0.0320	—	3.092	323.4
21	0.0285	—	2.452	407.8
22	0.0253	—	1.945	514.2
24	0.0201	—	1.223	817.7
26	0.0159	—	0.7692	1,300
28	0.0126	—	0.4837	2,067
30	0.0100	0.0003042	0.3042	3,287
32	0.0080	0.0001913	0.1913	5,227
34	0.0063	0.0001203	0.1203	8,314
36	0.0050	0.00007568	0.07568	13,210

Basis: Calculated estimates for solid, bare, round copper using nominal AWG dimensions and the standard annealed-copper density of approximately 0.321 lb/in³ (8.89 g/cm³) at 68°F (20°C), consistent with the National Bureau of Standards’ Copper Wire Tables. Values are rounded independently. Weights exclude insulation, plating, shielding, jackets, and spools.

What the Copper Wire Weight Chart Measures

American Wire Gauge, or AWG, identifies conductor size. Lower gauge numbers mean thicker wire; the “aught” sizes, written with /0, extend the scale beyond ordinary numbered gauges.

For a given material and length, weight follows the amount of metal in the cross-section. Doubling a round wire’s diameter gives it four times the cross-sectional area, and approximately four times the weight per foot.

The chart’s columns answer different buying and measuring questions:

• Pounds per foot: Use this to calculate the copper weight of a measured length.
• Pounds per 1,000 feet: Use this for longer runs and specifications written as lb/kft.
• Feet per pound: Use this to estimate how much bare wire remains in a coil.
• Bare diameter: Use this for solid round wire, not the outside diameter of insulation or a stranded bundle.

AWG does not identify the metal. Brass, bronze, copper-clad aluminum, and copper-clad steel should not be assigned ordinary copper-wire weights merely because their gauge matches. Standard copper-table values do not apply to every copper alloy.

Identify the material from the stock description, packaging, or product documentation before treating an AWG lookup as a copper-weight estimate. A copper-colored surface alone does not establish the composition beneath it.

How to Calculate Copper Wire Weight

Copper wire weight comes from its measured length and an appropriate weight factor, with each conductor calculated separately in a cable.

Step 1: Identify the Wire and Measure Its Length

1. Record the wire’s material, AWG size, and construction: solid, stranded, insulated, or shaped.
2. Measure the length in feet, or use a reliable marked length from the spool.
3. Decide whether you need the copper’s weight or the complete product’s weight.

That last distinction changes the calculation. A copper-content estimate is useful for material planning or scrap calculations. Shipping weight also includes insulation, jackets, packaging, and the reel.

If you are calculating the copper inside a cable, identify each conductor size. Do not assume that every conductor, including the grounding conductor, has the same gauge.

Step 2: Select a Weight Factor

1. For solid, bare, round copper, choose the AWG row and use its listed weight factor.
2. For a specified stranded or finished-wire product, use its documented weight per unit length when available. Make sure that figure represents the copper alone or the complete wire, whichever you need.

When a direct chart row is unavailable, an old estimating shortcut can help. For example, about 25.3 lb per 1,000 feet is a quick estimate for 11 AWG copper wire.

The shortcut is to double the original gauge number and use that wire size’s diameter in mils as the approximate pounds per 1,000 feet. For 11 AWG, double the gauge number to get 22 AWG; its diameter is about 25.3 mils. A mil is one-thousandth of an inch.

This National Bureau of Standards shortcut is for rough estimating. It does not replace a calculation from the actual dimensions or a measured sample when weight accuracy matters.

Step 3: Multiply by Length and Total the Conductors

1. Multiply the measured length by the weight per foot: Weight (lb) = length (ft) × weight per foot (lb/ft)
2. If using a pounds-per-1,000-feet figure, divide the length by 1,000 before multiplying.
3. For a cable containing several copper conductors, calculate each conductor’s weight and add the results.

For example, 500 feet of bare 12 AWG copper weighs approximately:

500 ft × 0.01977 lb/ft = 9.885 lb, or about 9.9 lb of copper.

Record the result as a copper-only estimate unless your weight factor explicitly includes the rest of the wire assembly. This keeps a material estimate from being mistaken for a shipping or finished-cable weight.

Weight Differences by Wire Construction

Stranded Copper Wire

Match copper weight to conductor construction, not just the AWG label.

A stranded conductor contains individual wires twisted together. Those strands follow a longer path than the finished conductor’s straight end-to-end length, and different strand combinations can produce slightly different amounts of copper at the same nominal gauge.

Stranded-wire notation gives the strand count followed by the AWG size of each strand. In that notation, 7/36 means seven strands of 36 AWG wire.

For a rough estimate, a solid-wire table provides a useful starting point. For a closer estimate, match the manufacturer’s exact strand construction or measure a sample. There is no single weight adjustment that accurately covers every stranded copper conductor.

Also, do not use a stranded bundle’s outside diameter as though it were a solid copper circle. That measurement includes spaces between strands.

Insulated Wire and Multiconductor Cable

Finished wire weighs more than its copper content because it also contains insulation and sometimes other materials. Multiconductor cables may add fillers, separator tapes, shielding, armor, and an outer jacket.

There is no dependable universal percentage to add for these components. Their contribution depends on the product’s construction, not just its conductor gauge.

For shipping or handling estimates, use the finished cable’s published weight per foot or per 1,000 feet. Check whether a listed spool weight is:

• Net wire or cable weight;
• Copper-conductor weight only; or
• Gross weight, including the reel and packaging.

A conductor-by-conductor calculation may also omit copper braid or foil shielding. If you need total recoverable copper rather than just conductor copper, those components need separate accounting.

Square and Half-Round Jewelry Wire

For equal outside dimensions:

• Square wire weighs about 1.273 times as much as round wire when the square’s side equals the round wire’s diameter.
• A true semicircular half-round wire weighs half as much as a full round wire with the same width.

These are geometric relationships, not universal gauge conversions. They work only when the finished dimensions match those definitions.

For flattened, oval, or domed wire, use its actual cross-sectional area or measure a sample. If a supplier’s gauge describes the original stock rather than the finished profile, the gauge alone is insufficient for calculating weight.

Copper Wire Diameter and Length Calculations

Bare diameter or cross-sectional area can estimate copper weight, while net wire weight and feet-per-pound can estimate remaining length.

Weight From Bare Diameter or Cross-Sectional Area

If a solid round copper wire has no reliable gauge marking, measure its bare diameter with a micrometer or suitable calipers. Do not include insulation or use a flattened or damaged portion as your measurement.

Using the standard wire-table density, the US-unit calculation is:

Weight (lb) ≈ 3.027 × diameter (in)² × length (ft)

Enter the diameter in inches, square it, and multiply by the length in feet and the constant. The result is the estimated copper weight in pounds.

Diameter accuracy matters because it is squared. A small diameter error produces a larger percentage error in calculated weight, especially with fine wire. Take measurements at more than one point and avoid squeezing soft copper with the measuring tool.

For wire specified by metric cross-sectional area, use:

Weight (kg) ≈ 0.00889 × area (mm²) × length (m)

The area must represent metal, not the insulated outside profile or the circle enclosing a stranded bundle. The US-unit and metric formulas use a standard copper density; they are not substitutes for identifying an unknown alloy.

Length From Net Wire Weight

To estimate the length remaining in a bare-wire coil:

1. Weigh the wire without packaging, ties, or a spool.
2. If the wire must remain on a spool, subtract the empty spool’s known weight.
3. Multiply the net copper weight by the chart’s feet-per-pound value.

Length (ft) = net copper weight (lb) × length per pound (ft/lb)

For example, a 0.25 lb coil of bare, round 20 AWG copper contains approximately:

0.25 lb × 323.4 ft/lb = 80.85 ft, or about 80.9 feet.

If your scale reads ordinary ounces, divide by 16 to obtain pounds. These are avoirdupois ounces, not troy ounces sometimes used for precious metals.

Do not apply bare-copper feet-per-pound figures to the gross weight of insulated wire. Without subtracting the non-copper mass, the result will overstate the available length.

How to Check Your Copper Wire Weight Estimate

When accuracy matters, measure samples of the copper actually being used rather than relying only on a table. This applies to both weight and resistivity determinations.

A nominal chart is useful for planning. A particular purchase, an unusual strand construction, a weight-sensitive project, or a scrap settlement may require greater precision.

Use this procedure to establish a weight factor for your stock:

1. Select a representative sample. Use a loose, disconnected piece from the same wire you are estimating. It should have the same material, gauge, and construction.
2. Measure its length accurately. Choose enough wire for its mass to register clearly on your scale. Very fine wire may require a longer sample than heavy wire.
3. Prepare it for the quantity you need. For copper-only weight, remove insulation without losing copper strands. For complete-wire weight, leave the construction intact.
4. Tare the scale and weigh the sample. Exclude any tray, bag, or other support from the net weight.
5. Calculate the measured weight factor. Divide the sample’s net weight in pounds by its length in feet.
6. Calculate the total. Multiply that measured pounds-per-foot value by the length of the remaining stock.

If the result differs substantially from the nominal chart, check material identification, dimensions, scale units, and tare weight before assuming the table is wrong. Copper cladding, an unexpected alloy, or included packaging can change the result considerably.

Record the measured weight factor alongside the wire’s gauge and construction, and label it as copper-only or finished-wire weight. Use that factor for the rest of the same stock.

Frequently Asked Questions

How Do You Determine the Gauge of Stranded Copper Wire?

The best starting point is the conductor marking or construction specification, not the outside diameter of the strand bundle. For an unmarked, disconnected sample with equal-size round strands, count the strands and measure one bare strand with a micrometer. Multiply that strand diameter by the square root of the strand count to obtain an equivalent solid diameter, then compare it with standard AWG diameters. Treat this as an estimate of nominal gauge, particularly for compacted or nonround strands.

What Is the Resistivity of Copper Wire?

Standard annealed copper at 68°F (20°C) has a resistivity of approximately 1.724 × 10⁻⁸ Ω·m, corresponding to 100% IACS conductivity. This is a material property, not the resistance of an entire wire: resistance also depends on conductor length and cross-sectional area. Temperature, composition, and processing can change the actual value, so accurate work requires measurements of the copper being used.

Can a Copper Wire Weight Chart Tell Me How Much Current a Wire Can Carry?

No, a weight chart is not an ampacity chart. Allowable current depends on conductor size, insulation temperature rating, installation conditions, ambient temperature, and applicable electrical requirements. Use an appropriate ampacity reference and the requirements for the actual installation rather than inferring current capacity from copper weight.