How much wattage can a coiled extension cord handle safely?

A fully uncoiled 14-gauge cord handles about 1800 watts (15 amps), but if it’s coiled, cut that in half to about 900 watts (7.5 amps). Coiling traps heat, which can melt insulation and start a fire. For a 50-foot run near 15 amps, use 12-gauge instead.