Downsizing fuse for LEDs

I just replaced three 100watt bulbs with three 15 watt LEDs, see pic below. These lights are not on a relay but on heavy wire with a 15amp fuse. My question is do I simply put in a 5amp fuse, now that I downsized the watts? It's like watts/volts=amps. Is that right to round up to 5amp fuse? 3*15/14.2=3.17