50% (half) of the moon's surface is illuminated at all times. At the time of New Moon, because of the moon's position between us and the sun, the illuminated half is turned completely away from us, and we can't see any of it.
At New Moon the percent illuminated is 0; at First and Last Quarters it is 50%; and at Full Moon it is 100%<span>. During the crescent phases the percent illuminated is between 0 and </span>50%<span> and during gibbous phases it is between </span>50%<span> and </span>100%<span>. so it depends on the phase
