What is bigger, 14 or 16 gauge wire?

Fourteen gauge is bigger than 16 gauge. AWG counts backwards, so every step down in number is a step up in copper.

The two live in different worlds. Fourteen AWG is the smallest building wire, running 15 amp lighting and receptacle circuits. Sixteen AWG is cord territory: light extension cords, lamp wire, speaker cable, good for roughly 10 to 13 amps in a cord and much less in bundled wiring.

The size gap is about 60 percent more cross-sectional area for the 14.

Doorbell and thermostat wire runs smaller still, at 18 and below. If the question is which one can serve a wall receptacle, the answer is only the 14.

Compare any two sizes side by side in the gauge to amps calculator.