WireGaugeCalc Free calculator · NEC cited · works offline
Awg To Amps Calculator
awg to amps calculator is fast with WireGaugeCalc, since you pick a gauge and it returns the rated amperes straight from NEC 310.16.
You set the conductor material and the termination temperature, so the result matches the column the inspector reads.
The payoff is a defensible ampere number you can size a breaker or load around without flipping through the table.
Open the calculatorSmallest conductor whose ampacity meets the load, NEC Table 310.16. Field aid only, verify against the current NEC and your local authority having jurisdiction.
How The Gauge To Ampacity Lookup Works
Each AWG size carries a fixed ampacity per NEC 310.16, so a clear gauge in means a clear ampere out.
Copper and aluminum differ, since aluminum carries less current at the same gauge.
The 60, 75, and 90 degree C columns set the ceiling, as your terminals decide which one applies.
What The Gauge To Amps Tool Asks For
Three inputs drive the rated ampere result:
- Conductor gauge in AWG, from 14 up through larger feeders
- Material, copper or aluminum, which shifts the ampacity
- Termination temperature, 60, 75, or 90 degrees C
- Reads the rated amperes directly from NEC 310.16
- Flags when 14, 12, and 10 AWG hit their small-conductor limits
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
Why does 12 AWG copper often show 20 amps and not 25?
The 75 degree C column lists 12 AWG copper at 25 amps, but NEC 240.4(D) caps small conductors, so the usable rating is 20 amps. Confirm the limit against the current NEC and your local authority having jurisdiction.
Should I read the 75 or 90 degree column?
Use the column that matches your weakest terminal, which on most equipment is 75 degrees C. The 90 degree value is mainly used for derating math, not for the final breaker size.
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.