Enter power in watts and voltage to get current in amps. Works for DC (solar panels, batteries), single-phase AC, and three-phase AC.
Breaker sizing uses the standard 125% continuous-load safety margin (NEC 210.19/210.20). Always verify against local code before wiring.
Watts measure total power, amps measure current flow, and volts measure electrical pressure — the three are linked by Ohm's and Watt's laws. This matters when sizing wire, breakers, or an inverter for a solar or battery system, since components are almost always rated in amps, not watts.
Power factor accounts for the phase difference between voltage and current in AC systems with motors or electronics. A power factor below 1 means more current is needed to deliver the same real power, so ignoring it undersizes your wiring.
It's the same relationship solved for the other variable — use this one when you know the wattage of a device or panel and need the current, and the amps to watts version when you know the current and need the power.