In most countries, the standard voltage for household outlets is 120 volts in North America and some parts of Central and South America, and 230 volts in most other parts of the world, including Europe, Asia, and Africa. However, it's important to note that there are variations and exceptions in different countries and regions. Additionally, the frequency of the alternating current (AC) can also vary, with 60 hertz (Hz) being common in North America and 50 Hz in many other regions. Always verify the specific voltage and frequency standards in your local area before using electrical devices.