Watt (W)

Quantity: Power · Category: Derived SI

The watt is the SI unit of power: one joule of energy transferred per second. It measures the rate of energy flow, not the total energy — named after steam-engine pioneer James Watt.

Relation to SI

1 W = 1 J/s = 1 kg·m²/s³

Examples

• A bright LED bulb draws about 10 watts.
• A microwave oven typically outputs 800–1,200 watts.