Watts Amps Volts Calculator
Enter real power, voltage, phase count, and power factor to estimate current and apparent power. This is arithmetic for planning, not a final equipment or code decision.
- Estimated current
- A
- Apparent power
- VA
- Apparent power
- kVA
- Phase multiplier
- x
Calculation details
- Power factor used
- PF
- Calculation basis
- Boundary
Recent results
Formulas
- Apparent power VA = real power watts / power factor
- Phase multiplier = 1 for single-phase; sqrt(3) for balanced three-phase
- Current amps = apparent power VA / (voltage x phase multiplier)
Use this calculator
Estimate current from watts, voltage, phase count, and power factor.
Read the result
Review the calculated values with their displayed units and assumptions. The result is a planning aid for the stated inputs, not a final equipment or installation decision.
Check before final work
This is a preliminary power formula estimate. Verify voltage basis, measured load, duty cycle, nameplate data, conductor sizing, protection, and local requirements before final design or installation decisions.
FAQs
Why does power factor change the current?
Power factor changes the apparent power needed to deliver the entered real power. Lower power factor means more current for the same watts.
What voltage should I use for three-phase?
Use line-to-line voltage for a balanced three-phase current estimate. Confirm the actual system and load connection before using the result.
Does this choose conductor size?
No. It estimates current from entered power assumptions only. Conductor and protection decisions need separate code, equipment, and job-condition review.