1500 W at 120 V
- Phase factor
- 1
- Power factor
- 1
- Power
- 1500 W
This is formula math only. Real electrical loads need correct voltage, power factor, breaker, wire, code, and professional review.
Watts to Amps Calculator
Use this free watts to amps calculator to estimate current from power, voltage, phase type, and power factor.
Research-backed assumptions Formula steps Examples included Private in-browser use
Formula steps
- Choose the formula based on DC, single-phase AC, or three-phase AC.
- Multiply voltage by the phase factor and power factor.
- Divide watts by that adjusted voltage value to estimate amps.
How to use the watts to amps calculator
- Enter watts, volts, phase/current type, and power factor.
- Press Calculate amps to estimate current draw.
- Use power factor 1 only when the load is DC or a simple resistive AC load.
- Check equipment nameplates, breakers, wiring, and code before real electrical work.
Common uses
Estimate current from a device watt rating.
Compare DC, single-phase, and three-phase examples.
Understand why AC power factor changes amps.
Check rough load math before using more detailed electrical tools.
Examples
12.5 A
About 10.19 A
About 16.34 A
Frequently asked questions
Plain-language answers about when to use the tool, what it does with your inputs, what to double-check, and how privacy works.
When should I use the Watts to Amps Calculator?
Use it when your task matches one of these common needs: Estimate current from a device watt rating. Compare DC, single-phase, and three-phase examples. It works best when you already know the values, dates, units, or settings the page asks for.
What is the Watts to Amps Calculator doing with my inputs?
In plain language: The calculator divides watts by volts for DC/single-phase loads, or by volts x sqrt(3) for three-phase loads, then includes power factor. The examples on the page are there so you can compare your inputs with a filled-out calculation before copying the answer.
What do the main Watts to Amps Calculator inputs mean?
Watts: real power used by the device or load. Volts: the supply voltage feeding the load. Phase: DC, single-phase AC, or three-phase AC changes the current formula. Power factor: how efficiently AC current becomes real power. Use 1 for DC or resistive loads.
How should I read the Watts to Amps Calculator answer?
Read the main answer first, then check the supporting lines and examples to understand how the calculator got there. If one input changes, rerun the tool and compare the new answer instead of guessing.
What should I double-check before trusting the answer?
This is formula math only. Real electrical work needs correct voltage, power factor, breaker, wire, code, and qualified review. Also check that you used the right unit, date, scale, or mode because small input changes can change the result.
Why does power factor matter?
Power factor matters for AC loads because not every amp becomes useful real power. A motor with 0.8 power factor needs more current than a resistive load using the same watts and volts.
Can I use this to choose a breaker size?
No. This helps you understand the math, but breaker and wire choices need code rules, equipment instructions, continuous-load rules, temperature, and qualified electrical review.
Does the site save what I enter?
No. The calculator runs in your browser tab. Your recent answers stay only on the page while you use it, and they are not sent to a server.
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