The answer to 'what size surge protector do I need' is that the size of surge protector you need depends on the electrical devices you want to protect and the power requirements of your home. As a general guideline, a 1,500-2,000 joule surge protector is suitable for most homes and small electronics like computers, TVs, and small appliances. For larger loads like refrigerators, air conditioners, or sensitive electronics, you may need a 3,000-4,000 joule surge protector.
When choosing a surge protector, also consider the number of outlets you need, the cord length, and any additional features like USB charging ports or coaxial/ethernet protection. It's important to select a surge protector that is UL-listed and has adequate joule rating and clamping voltage for your needs. If you're unsure, it's best to consult a licensed electrician who can assess your home's electrical system and provide a recommendation.