Let

c = 300,000 km/s is the speed of the light

t = 365 days = 365*24*60*60 = 31,536,000 s

d = the distance that the light travels

Since speed = distance/time follows distance = speed*time or:

d = 300,000*31,536,000

d = 9,460,800,000,000 km

In one year the light will travel 9,460,800,000,000 km.