WireGaugeCalc Free calculator · NEC cited · works offline
House Load Calculator Appliances
House load calculator appliances is simple with WireGaugeCalc, which totals appliance and general loads into a service demand figure.
Enter the dwelling square footage and the fixed appliances, and the tool applies the standard demand factors.
You get a total demand in amps, so you can confirm the service size you need.
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.
Add Up Dwelling Loads the NEC Way
The calculator follows the standard dwelling-unit method, since the NEC sets general lighting at 3 VA per square foot plus required circuits.
Fixed appliance loads are summed and the four-or-more demand factor applies, so the result reflects real demand rather than connected load.
The larger of the heating or air conditioning load is included, since both rarely run at the same time.
Loads the Calculator Adds Together
The service demand is built from the standard load categories:
- General lighting at 3 VA per square foot
- Two small-appliance circuits and one laundry circuit
- Fixed appliances such as a water heater or disposal
- Range or cooktop demand load
- The larger of heating or air conditioning
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
Do I count every appliance at full nameplate watts?
Not for the fixed-appliance group. When four or more fixed appliances are on the service, a demand factor reduces their combined load. Confirm which appliances qualify against the current NEC and your local authority having jurisdiction.
Should I add both heating and air conditioning loads?
No. You include only the larger of the two, since heating and cooling do not run at the same time. The calculator picks the larger value when you enter both.
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.