WireGaugeCalc Free calculator · NEC cited · works offline
Guage To Amps
Guage to amps is simple with WireGaugeCalc.
You enter the AWG wire size, choose copper or aluminum, and the calculator reads the ampacity from NEC Table 310.16.
Since each gauge carries a fixed current rating per temperature column, the result tells you what that conductor can safely handle.
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.
Matching Wire Gauge To Ampacity
Ampacity rises as the gauge number drops, so a larger conductor like 6 AWG carries more than a smaller 10 AWG.
Copper carries more current than aluminum at the same gauge, so the material choice shifts the amps you read.
The termination temperature column sets the usable value, since NEC 110.14(C) limits you to the rating of the lowest-rated termination.
What Changes The Amps For A Given Gauge
Several factors move the ampacity for one wire size:
- Copper versus aluminum at the same AWG.
- The 60C, 75C, or 90C termination column in NEC 310.16.
- Ambient temperature correction factors above 30C.
- Bundling more than three current-carrying conductors.
- Continuous loads, which require the 125% adjustment.
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
How many amps can 10 AWG copper carry?
10 AWG copper is rated 30 amps in the 60C column and 35 amps at 75C in NEC Table 310.16. Most breaker terminations limit it to 30 amps, so that is the common usable value. Confirm against the current NEC and your local authority having jurisdiction.
Why do I read a higher amp value than I can actually use?
The 90C column is for derating math, not for loading the wire. You must size to the termination temperature rating, which is usually 75C for circuits over 100 amps and 60C below it.
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.