WireGaugeCalc Free calculator · NEC cited · works offline
How Many Amps Is Hp
How many amps is hp is fast with WireGaugeCalc, since it converts motor horsepower into full-load current using voltage and phase.
You enter the horsepower, the system voltage, and whether the motor is single-phase or three-phase, so the result reflects the real load.
The output gives you the amps you need to size conductors and overcurrent protection with confidence.
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.
Turn 15 Hp To Amps With Voltage And Phase
Horsepower alone does not give amps, so the calculator asks for voltage and phase to finish the math.
A 15 hp to amps result changes a lot between 230V single-phase and 480V three-phase, since higher voltage lowers current for the same power.
Each answer is tied to the termination temperature column you select, so the ampacity you read matches NEC 310.16.
Why 15hp To Amps Depends On The Setup
Several inputs shape the current draw of a motor:
- Voltage, since current drops as voltage rises for the same horsepower
- Phase, because three-phase pulls less current than single-phase
- Motor full-load amps from NEC Table 430.250 rather than nameplate alone
- Termination temperature, since the 60C or 75C column sets conductor ampacity
- Conductor material, copper or aluminum, which changes the wire size
- Service factor and starting load, which affect protection 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
Why is 15 hp to amps different on 230V versus 480V?
Current is power divided by voltage, so a higher voltage carries the same horsepower at fewer amps. That is why a 15 hp motor draws roughly half the current at 480V compared to 230V.
Should I use nameplate amps or the NEC table value?
Use the full-load current from NEC Table 430.250 to size conductors and branch-circuit protection, since the code requires it. Verify the value against the current NEC and your local authority having jurisdiction before final sizing.
Does this include motor starting current?
The full-load amps cover running load, not inrush. Overload and short-circuit protection are sized separately, so check the motor article for the multipliers that apply.
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.