PlugVoltage

Travel power guide

What Happens If You Plug 110V Into 220V?

Direct answer

What Happens If You Plug 110V Into 220V?

A 110–120V-only device plugged into 220–240V receives roughly double the voltage it was built for, which can make it overheat, smoke, or catch fire.

Power scales with the square of voltage, so doubling the voltage can roughly quadruple the power through a simple heating element — which is why hair dryers and irons are the most dangerous.

A plug adapter does not help: it changes the plug shape, not the voltage. The device still receives the full local voltage.

If your device is single-voltage 120V, use a step-down voltage converter rated above its wattage, or — for heating tools — buy a dual-voltage travel version instead.

Failure examples

What over-voltage can do

A wrong-voltage plug-in is not a slow compatibility issue; it can fail immediately.

Simple heating element A 120V-only heat device on 230V can draw far more power than designed.
Motor appliance Single-voltage motors may overheat, run incorrectly, or fail under the wrong voltage/frequency.
Modern charger If it says 100-240V, the charger is built for this range; the remaining issue is plug shape.
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Related guides

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Guidance only — not professional electrical advice. Always confirm against your device's label before plugging in. Local wiring (especially in hotels and older buildings) can vary.