WireGaugeCalc Free calculator · NEC cited · works offline
Full Load Amps Calculator
Full load amps calculator is fast with WireGaugeCalc, since you enter horsepower or watts, voltage, and phase and it returns the running current.
It applies the standard motor current math so you can size conductors and protection around it.
You get the full load amps before you pull wire to the motor.
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.
An FLA calculator built on real motor math
The tool uses voltage, power, and power factor, since those drive the current a motor draws.
It handles single phase and three phase, so the 1.732 factor is applied when you need it.
Knowing the full load amps lets you set conductor and overload sizing correctly.
From horsepower to current in one step
WireGaugeCalc covers the inputs that set motor current:
- Horsepower or watts input
- Single phase and three phase
- Voltage from 120 up to 480 and beyond
- Power factor and efficiency adjustments
- Running current in amps
- A starting point for conductor and overload sizing
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
Should I use nameplate FLA or table values for sizing?
Use the motor nameplate FLA for overload protection and the NEC table values for conductor and branch-circuit sizing. This FLA calculator gives a calculated figure you can check against both. Confirm with the current NEC and your local authority having jurisdiction.
How does three phase change the calculation?
Three phase current divides the power by voltage, power factor, and the square root of three, which is about 1.732. The calculator applies that factor when you select three phase.
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.