WireGaugeCalc Free calculator · NEC cited · works offline
Electrical Load Calculator App
electrical load calculator app is fast with WireGaugeCalc, since it totals your connected loads and converts them to amps right in the browser.
You enter each load in watts or volt-amps, set the voltage, and the calculator sums them so you see the demand on the circuit or panel.
The result gives you a clear amp figure to compare against your overcurrent device and conductor rating.
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.
How the load and demand math works
The app divides total volt-amps by system voltage, so the current it shows reflects every load you added together.
Continuous loads get a 125 percent factor, since the NEC requires that margin for loads running three hours or more.
You can adjust each entry and watch the total amps change, which makes panel and feeder sizing quicker.
What the calculator handles for service and feeder sizing
Use it to move from a list of loads to a defensible amp total:
- Sums lighting, receptacle, and appliance loads into one figure
- Applies the 125 percent continuous-load factor where it belongs
- Converts watts and volt-amps to amps at your chosen voltage
- Helps compare the result to a breaker and conductor rating
- Works for single-phase and three-phase voltages
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
Does this size a whole electrical service?
It gives you the total connected and demand load in amps, which is the core of a service calculation. Full dwelling service sizing also uses the standard or optional method, so verify the final figure against the current NEC Article 220 and your local authority having jurisdiction.
How do I treat a continuous load?
Enter the load at its full rating and apply 125 percent, since a load running three hours or more must be counted that way for the conductor and overcurrent device.
Can I mix watts and volt-amps?
Yes, the app converts both to a common base before summing, but for motors and other reactive loads use volt-amps so the current is not understated.
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.