The wattage (power consumption) of an LED can be easily calculated using Ohms Law.

**P = V x I**

Where

**P** = power in watts consumed by the LED

**V** = the forward voltage rating of the LED (Vf)

**I** = the current used to drive LED

For example, the forward voltage of an LXML-PWC2 LED is 2.9 Vf. If you are powering the LED at 700mA (0.7A), then the power consumption for the LED will be 2.1W.

**2.9 x 0.7 = 2.03W**

Note that unlike traditional incandescent lighting, which typically equates light output to wattage; the wattage of an LED is only an expression of its *power consumption,*** not **its* light output*. Light output for LEDs is always expressed in Lumens. Not watts.