12-gauge is the safe bet for a lawn mower.

Go with 12-gauge. Here’s the short version: the longer the cord, the thicker it needs to be to avoid voltage drop. A lawn mower pulls a decent amount of current, especially when the grass is thick or the motor is starting up. A 14-gauge cord can work for a 25-foot run, but anything longer and you risk the mower running sluggish, tripping breakers, or overheating the cord.

Real-world test: I’ve seen a 14-gauge 100-footer make a mower sound like it’s struggling. Switched to 12-gauge, same distance, mower ran fine. The price difference is usually a few bucks. Don’t pinch pennies here.

If you’re only mowing within 25 feet of an outlet, 14-gauge is fine. But if you’re dragging the cord across the yard, get 12-gauge and call it done.

Your mower will thank you.