Power Calculator
Calculate power, voltage, or current from any two known values. Includes energy and battery runtime calculations.
Live
Input
Power
20.00 W
1.000 V × 20.000 A = 20.00 W
Example input:
1.0 V × 20 A = 20 WResults
Engineering Notes
Ohm's Law
V = I × R, P = V × I, P = I² × R, P = V²/R. These four equations relate voltage, current, resistance, and power. This calculator uses P = V × I as the primary relationship.
Battery Capacity Units
Battery capacity is often given in mAh (milliamp-hours). To convert to Wh: Wh = mAh × V / 1000. A 3000 mAh battery at 3.7V = 11.1 Wh.
This tool is intended for engineering analysis and educational purposes. Values and interpretations should be validated against the applicable JEDEC, PCI-SIG, NVM Express, MIPI, vendor datasheet or other authoritative specification.