WireGaugeCalc Free calculator · NEC cited · works offline
10 Gauge Wire Amps
10 gauge wire amps are quick to confirm with WireGaugeCalc, since the app reads the NEC 310.16 column that matches your termination temperature.
You choose copper or aluminum and the temperature rating, then the app shows the rated ampacity for 10 AWG.
You see the number tied to the right column, so the 10 wire amp rating you use is the legal one.
Open the calculatorAllowable ampacity from NEC Table 310.16 at the chosen termination temperature. Field aid only, verify against the current NEC and your local authority having jurisdiction.
How termination temperature sets the 10 gauge wire amperage load
Each conductor sits in three columns at 60, 75, and 90 degrees C, so the same 10 AWG wire has three different table values.
You size to the lowest-rated termination in the circuit, so a 75 degree C breaker caps a 90 degree C wire at the 75 column.
The app applies the column you pick, so the rating you read matches the equipment on both ends.
What the table gives for 10 AWG copper
Copper 10 AWG ampacity by NEC 310.16 column:
- 30 amps at the 60 degree C column
- 35 amps at the 75 degree C column
- 40 amps at the 90 degree C column
- Used at 30 amps for most general branch circuits
- Aluminum 10 AWG rates lower across all columns
- Ampacity adjustments apply for heat or bundling
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
Can 10 gauge wire carry 40 amps?
The 90 degree C column lists 10 AWG copper at 40 amps, but you can only use that value if every termination is rated 90 degrees C, which is rare. Most installs are limited to 30 amps for 10 AWG, so verify against the current NEC and your local authority having jurisdiction.
Why is 10 gauge wire often called a 30 amp wire?
Standard breakers and lugs are rated 75 degrees C or less, so the 60 degree C value of 30 amps governs most 10 AWG circuits. That is why a 30 amp circuit is the common 10 wire amp rating in the field.
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.