Watt's Law Calculator | P, V & I Solver
Quickly solve for Power (Watts), Voltage (Volts), or Current (Amps). A clean, precise utility for students, electricians, and hobbyists.
Relationship Visualizer
This chart visualizes how Power output increases linearly as Current rises (at a constant Voltage).
The Formula
P = V × I. This allows you to find any missing electrical variable in a DC circuit.
Safety First
Calculating power helps prevent overloading circuits and ensures correct wire sizing.
Understanding Watt's Law
Watt's Law defines the relationship between power, voltage, and current. Named after James Watt, it is a fundamental pillar of electrical engineering used for everything from DIY electronics to industrial power grids.
Power (P) Measured in Watts (W). Rate of energy transfer.
Voltage (V) Measured in Volts (V). Electrical potential difference.
Current (I) Measured in Amperes (A). Charge flow rate.
Calculations Summary
- Find Power: Select "Power" and enter V and I. $P = V \times I$.
- Find Voltage: Select "Voltage" and enter P and I. $V = P / I$.
- Find Current: Select "Current" and enter P and V. $I = P / V$.