Use 14-gauge for a lawn mower.

16-gauge is too thin for a lawn mower. Electric mowers draw a decent amount of current, especially on startup, and thin wire creates voltage drop that can prevent the motor from starting or cause it to overheat over a long run.

14-gauge handles the load fine for most residential mowers up to maybe 100 feet. If your run is longer (150+ feet) or your mower is a heavy-duty model, step up to 12-gauge. The difference is about $5-10 more for the thicker cord.

Don’t risk a fire or a dead mower to save a few bucks.