WireGaugeCalc Free calculator · NEC cited · works offline
Multiple Wire Gauge Calculator
Multiple wire gauge calculator work is fast with WireGaugeCalc.
You enter each circuit load with its material and termination temperature, and the calculator sizes every conductor against NEC 310.16 ampacity.
So you size a whole panel of circuits in one pass instead of one at a time.
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.
Sizing Several Runs With A Combined Wire Gauge Calculator
Each circuit has its own load and length, so a combined wire gauge calculator keeps the values separate and reads the right column for each.
When two runs share the same breaker rating, the conductor can still differ if one run is long enough to need a voltage drop bump.
The calculator flags the gauge per circuit so nothing gets undersized.
What The Calculator Checks Per Conductor
For every run entered the tool reviews:
- Load amps against NEC 310.16 ampacity
- Conductor material, copper or aluminum
- Termination temperature column at each end
- Run length so voltage drop is caught
- Insulation type for the printed rating
- Derating from ambient 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 I size different circuits with different materials at once?
Yes, each entry holds its own material, so you can mix copper and aluminum runs in the same batch. The calculator reads the correct ampacity column for each conductor.
Will it warn me when a long run needs a larger gauge?
It checks run length so voltage drop on long circuits pushes the suggested gauge up. Treat the result as a starting point and verify against the current NEC and your local authority having jurisdiction.
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.