Copper Wire — AWG, Weight, and Resistance
AWG (American Wire Gauge) uses a logarithmic scale where smaller numbers mean larger wires. Copper density is 8,960 kg/m³. Wire weight = volume × density; resistance R = ρL/A. Each 3-gauge decrease doubles cross-sectional area.
Did our AI summary help? Let us know.
AWG uses logarithmic scale — 3 gauges = 2× area change Copper density 8,960 kg/m³; aluminum 2,700 kg/m³ (60% lighter) Aluminum has 1.6× higher resistivity than copper Resistance increases with temperature: R(T) = R₀(1 + αΔT)
Ready to run the numbers?
Why: Wire weight and resistance calculations are essential for electrical design, cable sizing, and cost estimation. AWG standardization enables consistent specifications across the industry.
How: Select AWG gauge (0000 to 40) and enter length. The calculator uses the full AWG database for diameter, area, resistance per unit length, and current capacity. Compare with aluminum for weight and resistance differences.
Run the calculator when you are ready.
🏠 Residential 12 AWG
100m of 12 AWG copper wire for home wiring
⚡ Power 6 AWG
500ft of 6 AWG copper wire for power distribution
🔌 Control 20 AWG
50m of 20 AWG copper wire for control circuits
🔗 Aluminum Comparison
1000ft of 10 AWG aluminum vs copper comparison
🔋 Large Cable 4/0
1km of 4/0 AWG copper wire for heavy power
🔌 Appliance 10 AWG
25ft of 10 AWG copper for appliance circuits
⚡ Subpanel 2 AWG
75ft of 2 AWG copper for subpanel feeder
🚗 Automotive 14 AWG
20ft of 14 AWG copper for automotive wiring
🌡️ High Temp Aluminum
500m of 8 AWG aluminum at 60°C
💻 Data Center 3/0
200ft of 3/0 AWG copper for data center power
🌊 Marine 4 AWG
50ft of 4 AWG copper for marine applications
☀️ Solar 8 AWG
100ft of 8 AWG copper for solar panel wiring
🔌 EV Charging 2 AWG
30ft of 2 AWG copper for EV charging station
🏭 Industrial 1 AWG
150ft of 1 AWG copper for industrial equipment
Enter Values
Wire Weight Results
Weight
6.536 lb
Resistance
5.0771 Ω/km
Current Capacity
Maximum current
AWG Gauge
2.053 mm
Detailed Properties
| Wire Type | Copper | AWG Gauge | 12 |
| Diameter (mm) | 2.0530 | Diameter (inches) | 0.080800 |
| Cross-sectional Area (mm²) | 3.3090 | Area (circular mils) | 6530.0 |
| Weight (kg) | 2.9649 | Weight (lb) | 6.5364 |
| Weight (g) | 2964.86 | Weight (oz) | 104.58 |
| Length (m) | 100.0000 | Length (ft) | 328.08 |
| Weight per km (kg/km) | 29.6486 | Weight per 1000 ft (lb/1000ft) | 19.9229 |
| Resistance (Ω) | 507.7063 mΩ | Resistance per km (Ω/km) | 5.0771 |
| Resistance per 1000 ft (Ω/1000ft) | 1.5475 | Current Capacity (A) | 20.0 |
Aluminum Wire Comparison
Aluminum Weight
0.8934 kg
1.9697 lb
Weight Difference
69.87%
Lighter
Aluminum Resistance
800.8462 mΩ
Resistance Difference
57.74%
Higher
Note: Aluminum wire is approximately 69.9% lighter than copper but has 57.7% higher resistance. For equivalent current capacity, aluminum wire typically needs to be one AWG size larger than copper.
AWG Comparison Charts
Weight per km by AWG
Resistance per km by AWG
Step-by-Step Calculation
AWG Gauge: 12
Wire Type: copper
Length: 100 m = 100.0000 m
Temperature: 20°C
Diameter: 2.053 mm (0.0808 inches)
Cross-sectional Area: 3.3090 mm²
Area: 6530.0 circular mils
Density: 8960 kg/m³ (Copper)
Cross-sectional Area: 3.30900000e-6 m²
Volume = Area × Length
Volume = 3.30900000e-6 m² × 100.0000 m
Volume = 0.00033090 m³
Weight = Volume × Density
Weight = 0.00033090 m³ × 8960 kg/m³
Weight = 2.9649 kg
Resistivity (20°C): 1.68e-8 Ω·m
Resistance = (Resistivity × Length) / Area
Resistance (20°C) = (1.68e-8 Ω·m × 100.0000 m) / 3.30900000e-6 m²
Resistance (20°C) = 507.7063 mΩ
For educational and informational purposes only. Verify with a qualified professional.
🔬 Physics Facts
AWG 0000 (4/0) has diameter 11.68 mm; AWG 40 has diameter 0.08 mm
— ASTM
Each 3-gauge decrease doubles cross-sectional area and halves resistance
— NIST
Aluminum is 60% lighter but needs 1.6× larger cross-section for same resistance
— Physics Classroom
Copper resistance increases ~0.4% per °C — critical for high-current applications
— NIST
📋 Key Takeaways
- • AWG (American Wire Gauge) uses a logarithmic scale - smaller numbers = larger wires
- • Copper density: 8,960 kg/m³ | Aluminum density: 2,700 kg/m³
- • Aluminum is 60% lighter but has 1.6× higher resistance than copper
- • Each 3-gauge decrease doubles the cross-sectional area and halves the resistance
- • Current capacity depends on AWG gauge, insulation type, ambient temperature, and installation method
💡 Did You Know?
📖 How Wire Weight Calculation Works
The weight of wire is calculated using the fundamental relationship: Weight = Volume × Density. For cylindrical wire, volume equals cross-sectional area times length.
Step-by-Step Process
- Select AWG gauge from database (determines diameter and area)
- Enter wire length and convert to meters
- Calculate volume: V = Area × Length
- Multiply by material density: Weight = V × Density
- Calculate resistance: R = (Resistivity × Length) / Area
- Apply temperature correction if needed
🎯 Expert Tips for Wire Selection
💡 Consider Voltage Drop
For long runs, voltage drop may require larger wire than current capacity alone. Maximum drop is typically 3-5% for branch circuits.
💡 Temperature Matters
Wire resistance increases with temperature. For high-temperature applications, use temperature-corrected resistance values.
💡 Aluminum Considerations
Aluminum requires special connectors and installation techniques to prevent oxidation. Always use one AWG size larger than copper.
💡 Weight for Installation
Calculate total wire weight for cable tray sizing, support system design, and installation logistics. Essential for large-scale projects.
⚖️ Copper vs Aluminum Comparison
| Property | Copper | Aluminum | Notes |
|---|---|---|---|
| Density | 8,960 kg/m³ | 2,700 kg/m³ | Aluminum 60% lighter |
| Resistivity | 1.68×10⁻⁸ Ω·m | 2.65×10⁻⁸ Ω·m | Aluminum 1.6× higher |
| Weight Savings | - | 60% | For same gauge |
| AWG Size Needed | Standard | +1 size | For same current |
| Cost | Higher | Lower | Per pound |
| Corrosion | Excellent | Good (with protection) | Aluminum needs special connectors |
❓ Frequently Asked Questions
What is AWG and how does it work?
AWG (American Wire Gauge) is a standardized wire gauge system. Smaller numbers represent larger wires. Each 3-gauge decrease doubles the cross-sectional area. AWG 0000 (4/0) is the largest standard size, AWG 40 is the smallest.
How do I choose the right wire gauge?
Wire gauge selection depends on current capacity, voltage drop limits, and installation method. Use NEC tables for current capacity. For long runs, voltage drop may require larger wire than current capacity alone.
Why does aluminum wire need to be larger than copper?
Aluminum has 1.6× higher resistance than copper. To carry the same current with the same voltage drop, aluminum wire must be one AWG size larger (which doubles the cross-sectional area).
How does temperature affect wire resistance?
Wire resistance increases with temperature. Copper has a temperature coefficient of 0.00393/°C. A 50°C rise increases resistance by about 12%. Always consider operating temperature for accurate calculations.
What is the difference between solid and stranded wire?
Solid wire is a single conductor, while stranded wire consists of multiple smaller wires. Stranded wire is more flexible but may have slightly higher resistance due to air gaps. Weight calculations assume solid wire.
How do I calculate voltage drop?
Voltage drop = I × R, where I is current and R is resistance. For AC circuits, also consider power factor and reactance. Maximum voltage drop is typically 3-5% for branch circuits, 1-2% for feeders per NEC.
What is the weight capacity of cable trays?
Cable tray capacity varies by type: ladder trays typically hold 50-200 lb/ft, while solid-bottom trays hold more. Calculate total weight of all cables in the tray to ensure capacity is not exceeded.
Can I use this calculator for other wire materials?
This calculator is designed for copper and aluminum. For other materials, you would need to adjust the density and resistivity values. The formulas remain the same: Weight = Volume × Density, R = (ρ × L) / A.
📊 AWG Wire by the Numbers
📚 Official Data Sources
⚠️ Disclaimer: This calculator provides estimates based on standard AWG properties and material constants. Actual wire properties may vary by manufacturer, insulation type, and environmental conditions. Current capacity values are conservative estimates. Always consult NEC (National Electrical Code) or local electrical codes for specific applications. Not a substitute for professional electrical engineering consultation.
Related Calculators
Gold Weight Calculator
Calculate gold weight by dimensions and karat purity. Convert between troy ounces, grams, and pennyweights for jewelry and bullion.
PhysicsAngle of Repose Calculator
Calculate angle of repose for granular materials. Analyze friction coefficient and slope stability for storage and handling design.
PhysicsAngle of Twist Calculator
Calculate angle of twist in shafts under torsional loading. Analyze shaft deformation for power transmission design.
PhysicsBend Allowance Calculator
Calculate bend allowance and K-factor for sheet metal fabrication. Determine flat pattern length for accurate bending operations.
PhysicsBrinell Hardness Number Calculator
Calculate Brinell hardness number (BHN) from indentation test data. Analyze material hardness and estimate tensile strength.
PhysicsBuckling Calculator
Calculate critical buckling load using Euler formula. Analyze column stability with various end conditions for structural design.
Physics