200 Amp Service Wire Size: What Gauge Wire Do You Need?
NEC-based wire gauge for a 200 amp mainbreaker — copper and aluminum sizes, ground wire, conduit, and when to upsize for voltage drop.
For a 200 amp residential service, use 2/0 AWG copper or 4/0 AWG aluminum wire (per NEC Table 310.12, the 83% rule for dwelling services).
Based on NEC Table 310.16 (75°C column) and, where noted, Table 310.12 for dwelling services. Confirm termination ratings and local amendments before installing.
200 Amp Wire Size at a Glance
| Copper wire size | 2/0 AWG (dwelling service per 310.12) |
|---|---|
| Aluminum wire size | 4/0 AWG (dwelling service per 310.12) |
| Breaker size | 200 amp main |
| Ground wire | #4 AWG copper GEC (Table 250.66); #6 Cu EGC on a 200A feeder |
| Typical conduit | 2" or 2-1/2" rigid/PVC service riser (three 4/0 XHHW conductors) |
Verify conduit fill for your exact conductor count and insulation type with the conduit fill calculator.
Common Uses for a 200 amp main Circuit
- Standard main service for new single-family homes
- Service upgrades from 100A/125A panels
- All-electric homes with EV charging and heat pumps
- Whole-dwelling feeders from meter-main combos to interior panels
- Large shop services
When to Upsize for Voltage Drop
Service conductors are usually short, so voltage drop rarely governs a 200A service itself. It matters for long whole-dwelling feeders — a meter pole 200 feet from the house, for example. At 240V and a realistic 120A demand, 4/0 aluminum stays under 3% to roughly 190 feet; for longer runs step up to 300 or 350 kcmil aluminum.
The NEC recommends (in informational notes to 210.19 and 215.2) keeping voltage drop under 3% on a branch circuit or feeder and 5% total. Ampacity tables ignore distance entirely, so on any run much past 100 feet, check the numbers with the voltage drop calculator before buying wire.
NEC References and Code Notes
- NEC Table 310.12 permits 83% sizing for 120/240V single-phase dwelling services: 200A service = 2/0 AWG copper or 4/0 AWG aluminum. This is the standard residential answer.
- Without the dwelling allowance (e.g., a 200A commercial feeder or a feeder not carrying the whole dwelling load), Table 310.16 at 75°C requires 3/0 copper (200A) or 250 kcmil aluminum (205A).
- The 83% rule also applies to a feeder between the meter-main and an interior panel when that feeder supplies the entire dwelling load — a common layout with exterior disconnects required by NEC 230.85.
- The grounding electrode conductor for a 200A service with 2/0 Cu or 4/0 Al conductors is #4 AWG copper per Table 250.66.
- A 200A feeder’s equipment grounding conductor is #6 AWG copper per Table 250.122.
See the NEC code reference for related articles. Always confirm requirements with your local authority having jurisdiction.
Frequently Asked Questions
Can I use 4/0 aluminum for a 200 amp service?
Yes — 4/0 AWG aluminum is the standard 200 amp residential service conductor, permitted by NEC Table 310.12 (the 83% rule for single-phase dwelling services). 4/0 aluminum SER or XHHW-2 in conduit are both common. Outside the dwelling-service allowance, 4/0 aluminum (180A at 75°C) is not enough for a 200A breaker.
Can 2/0 copper carry 200 amps?
Only for a dwelling service or whole-dwelling feeder. 2/0 copper is rated 175A at 75°C in Table 310.16, so a standard 200A feeder needs 3/0 copper. NEC Table 310.12 permits 2/0 copper at 200A specifically for single-phase dwelling services and feeders that supply the entire dwelling load — the diversity of whole-house demand justifies the 83% sizing.
What size ground wire for a 200 amp service?
The grounding electrode conductor (to ground rods and water pipe) is #4 AWG copper per NEC Table 250.66 for 2/0 copper or 4/0 aluminum service conductors. If you are running a 200A feeder to a sub panel instead, the equipment grounding conductor is #6 AWG copper per Table 250.122.
What size conduit for a 200 amp service?
Three 4/0 XHHW-2 aluminum conductors fit in 2" conduit per Chapter 9 fill calculations, but most electricians and many utilities use 2-1/2" for easier pulling and to satisfy utility service-lateral specs. Check your utility’s service requirements — they frequently dictate riser size, conductor type, and meter placement.
Is a 200 amp service worth it over 150 amp?
Almost always. The incremental cost of 200A over 150A is small — slightly larger conductors and panel — while the headroom covers EV charging, heat pump conversion, and induction cooking without a future upgrade. For new construction and full service replacements, 200A is the default recommendation.
Related Tools and Wire Size Guides
Wire Sizing Calculator
Calculate the exact wire gauge for any load, voltage, and distance per NEC tables.
Calculate Wire Size →Voltage Drop Calculator
Check whether your run length forces a larger conductor than ampacity alone requires.
Calculate Voltage Drop →Wire Ampacity Chart
Full NEC Table 310.16 ampacities at 60°C, 75°C, and 90°C for copper and aluminum.
View Ampacity Chart →Breaker Size Calculator
Find the right breaker for a given load, including the 125% continuous-load rule.
Size a Breaker →30 Amp Wire Size: What Gauge Wire Do You Need?
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Read the Guide →40 Amp Wire Size: What Gauge Wire Do You Need?
For a 40 amp circuit, use #8 AWG copper or #6 AWG aluminum wire (THWN/THHN rated at 75°C).
Read the Guide →50 Amp Wire Size: What Gauge Wire Do You Need?
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