How dense is copper? Pure copper has a density of about 8.96 g/cm3 (8,960 kg/m3) at room temperature. In US units, that is about 0.324 pounds per cubic inch or 559 pounds per cubic foot. So copper is almost 9 times as dense as water, while most brass and bronze is slightly lighter.
Convert Copper Density to Any Unit
Generally speaking, chemistry books give density in grams per cubic centimeter. Machinists and electricians in the US, however, usually think in pounds per cubic inch or per cubic foot. So enter 8.96 for pure copper, 8.5 for a typical brass, or your own measured value, and the converter shows every common unit at once.
Put simply, density is mass divided by volume. For copper, it tells you how much a piece weighs for the space it fills. As a result, the number lets you turn a size into a weight: the weight of a spool of wire, a length of pipe, a bus bar or a sheet of roofing.
To begin with, copper is a soft, reddish metal with atomic number 29. In addition, its atoms pack into a face-centered cubic crystal, which is one of the tightest ways to stack spheres. That tight packing, together with an atomic weight of about 63.5, explains why the metal feels heavy in the hand. For example, the Royal Society of Chemistry copper element page lists its density as 8.96 g/cm3.
In short, use 8.96 g/cm3 for pure copper unless a standard or a supplier gives you something else. Next, you will find the value in every unit, the ranges for brass and bronze, and worked wire and pipe weights.
How Dense Is Copper in Different Units?
All of the values below come from the same number, 8.96 g/cm3, converted with the exact definitions of the pound (453.59237 g) and the inch (2.54 cm). Because 1 g/cm3 equals 1 g/mL and 1 kg/L, the first three rows share the same figure.
| Unit | Pure copper | What it means |
|---|---|---|
| g/cm3 | 8.96 | A 1 cm cube weighs 8.96 g |
| g/mL and kg/L | 8.96 | 1 liter of solid copper weighs 8.96 kg |
| kg/m3 | 8,960 | A 1 m cube weighs almost 9 metric tons |
| lb/in3 | 0.3237 | A 1 in cube weighs about 146.8 g (5.18 oz) |
| lb/ft3 | 559.4 | A 1 ft cube weighs about 559 lb (253.7 kg) |
| lb/gal (US) | 74.8 | A gallon-sized block weighs almost 75 lb |
Also, compare it with water at about 1.00 g/cm3, or 62.4 lb/ft3. Therefore, the specific gravity of copper is about 8.96, which is just the density divided by the density of water.
How Dense Is Copper Compared With Brass and Bronze?
First, brass is copper mixed with zinc, and bronze is copper mixed mainly with tin, aluminum or other elements. Because zinc, tin and aluminum are all lighter than copper, the alloys usually come in a little lower. However, the exact figure depends on the recipe, which is why tables give ranges instead of one number.
| Material | g/cm3 | lb/in3 | lb/ft3 |
|---|---|---|---|
| Pure copper | 8.96 | 0.324 | 559 |
| Cartridge brass (70% Cu, 30% Zn) | 8.53 | 0.308 | 533 |
| Yellow brass | 8.47 | 0.306 | 529 |
| Most brasses (typical range) | 8.4 – 8.73 | 0.303 – 0.315 | 524 – 545 |
| Phosphor bronze | 8.78 – 8.92 | 0.317 – 0.322 | 548 – 557 |
| Aluminum bronze | 7.7 – 8.7 | 0.278 – 0.314 | 481 – 543 |
The alloy figures follow the Engineering ToolBox metal and alloy density table. In practice, aluminum bronze shows the widest spread, because aluminum is so much lighter than copper that a few percent moves the total a lot.
Recommended Tools for Checking Copper Density
To find density yourself, you need a mass and a volume. First, a pocket scale that reads to 0.01 g handles small parts and wire samples. Next, a digital caliper measures diameters and thickness for regular shapes. In addition, a wire gauge plate for non-ferrous metals identifies AWG sizes, and a graduated cylinder measures the volume of odd shapes by water displacement.
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How Dense Is Copper Wire? Weight Examples
Above all, wire weight is where copper density matters most in daily work. To get it, multiply the cross-sectional area by the length and then by the density. For instance, 12 AWG wire is 0.0808 in across, so its area is about 0.00513 square inches. One thousand feet (12,000 in) therefore holds about 61.5 cubic inches of copper, which weighs close to 20 lb.
| Size (solid, bare) | Diameter | lb per 1,000 ft | kg per km |
|---|---|---|---|
| 14 AWG | 0.0641 in (1.63 mm) | 12.4 | 18.5 |
| 12 AWG | 0.0808 in (2.05 mm) | 19.8 | 29.4 |
| 10 AWG | 0.1019 in (2.59 mm) | 31.4 | 46.8 |
| 8 AWG | 0.1285 in (3.26 mm) | 50.0 | 74.4 |
| 6 AWG | 0.1620 in (4.11 mm) | 79.5 | 118.3 |
These weights match the NIST copper wire tables (NBS Handbook 100), which list 19.8 lb per 1,000 ft for 12 AWG. However, they cover the bare conductor only. Insulation, jackets and stranding therefore add weight, so a real cable weighs more.
The same math works for other shapes. For example, a copper tube with a 0.625 in outside diameter and a 0.040 in wall weighs about 0.29 lb per foot. Similarly, “16 oz” roofing copper weighs 1 lb per square foot, which works out to a sheet about 0.0215 in (0.55 mm) thick.
How Dense Is Copper Next to Other Metals?
Overall, copper sits in the middle of the common metals. It is denser than steel, but far lighter than gold or tungsten.
| Metal | g/cm3 | Compared with copper |
|---|---|---|
| Aluminum | 2.70 | Copper is about 3.3 times denser |
| Steel | 7.85 | Copper is about 14% denser |
| Nickel | 8.91 | Almost the same |
| Copper | 8.96 | – |
| Silver | 10.49 | About 17% denser than copper |
| Lead | 11.34 | About 27% denser than copper |
| Tungsten | 19.25 | About 2.15 times denser |
| Gold | 19.32 | About 2.16 times denser |
So a gold bar the same size as a copper bar weighs a little more than twice as much. Our guides on how dense gold is and how dense tungsten is explain why those two metals are almost identical, which is also why fake gold bars sometimes hide a tungsten core.
Density does not explain why copper conducts electricity and heat so well, though. Instead, it comes from its free electrons, not its weight. In fact, aluminum conducts less per wire size but more per pound, which is why overhead power lines often use aluminum.
How to Find How Dense Copper Is at Home
You can check a copper part with the water displacement method. Here is how:
- Clean and dry the sample. Remove dirt, oil and loose insulation so you only weigh metal.
- Weigh it in grams. Next, place the piece on a scale that reads to 0.01 g and write down the mass.
- Fill a graduated cylinder. First, add enough water to cover the piece, then read the level at eye height.
- Lower the sample in gently. Tilt the cylinder and slide the piece down the side so no water splashes out.
- Read the new level. As a result, the rise in milliliters equals the volume of the sample in cubic centimeters.
- Divide mass by volume. For example, 44.8 g that raises the water 5.0 mL gives 8.96 g/cm3, so the piece is very likely copper.
Alternatively, for a wire or rod, you can skip the water. Instead, measure the diameter with a caliper, calculate the volume of a measured length, and then divide the weight by that volume. Finally, enter your result in the converter above to see it in pounds per cubic inch.
Do and Don’t When Testing Copper
Do
- Use a large sample, because errors shrink as volume grows.
- Knock air bubbles off the piece before reading the level.
- Also read the bottom of the water curve at eye level.
- Finally, repeat the test and average the results.
- Most importantly, compare against a range, not one exact number.
Don’t
- Test a modern US penny and expect copper.
- Include insulation or plating in the weight.
- Trust a reading from a part with hollow spaces, because the voids add volume.
- Assume a reddish color means pure copper, since some brass and bronze look similar.
- Drop the part in and splash water out.
Honest Limits on How Dense Copper Is
Of course, the 8.96 figure is a good reference, but it is not the only one. For instance, the International Annealed Copper Standard behind US wire tables uses 8.89 g/cm3 at 20 C, and some engineering tables list 8.94. Specifically, these small gaps come from purity, cold working and the reference temperature. Meanwhile, heat also matters: copper expands by about 0.5% in volume for every 100 C rise, so hot copper is slightly less dense. Because of all this, a home measurement within about 2% of 8.96 is as close as most people can get.
When Accuracy Really Matters
For a science project or a rough scrap estimate, 8.96 g/cm3 is certainly plenty. In contrast, three cases call for more care. First, engineering loads and shipping weights for cable and bus bar should use the manufacturer’s published weight per length. Second, scrap and metal buyers grade copper by purity, so they rely on analyzers rather than density alone. Third, electrical work must follow the code and the cable maker’s ratings, not a weight estimate.
Frequently Asked Questions
How dense is copper in g/cm3?
Pure copper has a density of about 8.96 g/cm3 at room temperature. In other words, that equals 8,960 kg/m3 or 8.96 g/mL.
What is the density of copper in lb/in3?
Copper weighs about 0.324 pounds per cubic inch. So a 1-inch cube of copper weighs about 146.8 grams, or 5.18 ounces.
How dense is copper in lb/ft3?
Copper has a density of about 559 pounds per cubic foot. Therefore, a solid 1-foot cube would weigh about 559 lb, or 253.7 kg.
Is brass denser than copper?
No. Most brass is about 8.4 to 8.73 g/cm3, slightly lighter than copper at 8.96, because zinc is lighter than copper.
Is bronze denser than copper?
Usually not. Phosphor bronze comes close at about 8.78 to 8.92 g/cm3, while aluminum bronze can be as low as about 7.7 g/cm3.
How much does 1,000 feet of 12 gauge copper wire weigh?
According to NIST wire tables, bare solid 12 AWG copper wire weighs about 19.8 pounds per 1,000 feet. Insulated cable weighs more because of the jacket.
How dense is copper compared with steel?
In fact, copper at 8.96 g/cm3 is about 14% denser than typical steel at 7.85 g/cm3.
Is copper denser than lead?
No. Lead is about 11.34 g/cm3, so it is roughly 27% denser than copper.
Does temperature change how dense copper is?
Yes, slightly. Copper expands when heated, losing about 0.5% of its density for every 100 C rise.
Why do some tables list copper at 8.89 or 8.94 g/cm3?
This is because different references use different purity, processing and temperature. US wire tables, for example, use 8.89 g/cm3 for annealed copper at 20 C.
How Dense Is Copper? The Bottom Line
To sum up, pure copper has a density of about 8.96 g/cm3, which is 8,960 kg/m3, 0.324 lb/in3 or 559 lb/ft3. Meanwhile, brass usually lands between 8.4 and 8.73 g/cm3, while bronze ranges from about 7.7 to 8.9 depending on the alloy.
So next time you need a weight, multiply the volume by the density, or use the converter at the top of this page to switch units. For wire, remember the quick rule: about 20 lb per 1,000 ft of bare 12 AWG copper.