WireGaugeCalc Free calculator · NEC cited · works offline
Size Of Al Conductors For 200 Amp Service
Size of al conductors for 200 amp service is simple with WireGaugeCalc, since the calculator is built into this page.
You set the service to 200A, pick aluminum, and choose the termination temperature column to get the conductor size.
That means you can confirm the aluminum AWG or kcmil before you order the cable.
Open the calculatorEnter any two values and read the rest.
Ohm’s law: V = I × R and P = V × I. Field aid only, verify against the current NEC and your local authority having jurisdiction.
Aluminum ampacity at 200 amps
Aluminum has higher resistance than copper, so it needs a larger size to carry the same 200A.
WireGaugeCalc reads the NEC ampacity tables and returns the aluminum size that fits the service rating.
Since dwelling services have their own allowance, the result can differ from the standard table.
What changes the aluminum service conductor size
A few inputs drive the answer:
- 200A service rating
- Aluminum conductor material
- 75C termination column for most lugs
- Single dwelling vs other occupancy
- Result shown as a kcmil or AWG size
One app for every NEC calculation
WireGaugeCalc keeps the calculations you reach for most in one place:
- Voltage drop and wire sizing for any run
- Conduit fill for EMT, PVC, and RMC
- Box fill and junction box sizing
- Ampacity and temperature derating
- Motor circuit and load calculations
- Conduit bend offsets and saddles
Built for the field, works offline
The whole app runs on your phone, so it keeps working in a basement, an attic, or a job site with no signal.
There is no account to create and nothing to load. Open it, run the number, and get back to work.
- No signup and no signal needed
- Answers in a tap, not a spreadsheet
- Same tool on phone, tablet, and desktop
Every result cites the NEC article
Each answer shows the table or formula it came from, so you can check the method and learn the code as you go.
That makes the app useful on the job and during exam prep, since the reasoning is right next to the number.
Switch the code year your job runs on
Jurisdictions adopt the NEC at different times, so you can match the calculation to the code in force:
- NEC 2017, 2020, and 2023 tables
- Copper and aluminum conductors
- 60, 75, and 90 degree C terminations
- Single-phase and three-phase systems
Run the number, then get back to work
Stop flipping through a paper book or hopping between calculator sites. Enter your values, read the code-cited answer, and move on. Free to use, no signup.
Open the calculatorFrequently asked questions
Is 4/0 aluminum enough for a 200 amp service?
4/0 aluminum is widely used for a 200A single-dwelling service under the NEC dwelling table. For other occupancies the standard ampacity table can call for a larger size, so verify against the current NEC and your local authority having jurisdiction.
Why does aluminum need a bigger size than copper here?
Aluminum carries less current per AWG size because its resistance is higher, so it takes a larger conductor to reach 200A. The calculator lets you compare aluminum and copper side by side.
Is WireGaugeCalc free to use?
Yes. Every calculator is free to run with no signup. A paid tier adds saved projects, PDF reports, and extra code years, but the core math stays free.
Does it work without internet?
Yes. The app runs on your device, so it keeps working with no signal on a job site, in a basement, or in an attic.
Are the results code accurate?
Results follow published NEC tables and standard formulas, and each answer shows the article it came from. It is a field aid, not a stamp of approval, so verify against the current code and your local authority before you wire anything.
Which NEC code year does it use?
You can switch between NEC 2017, 2020, and 2023, since jurisdictions adopt the code at different times. Pick the year your job runs on.