The answer to 'what size ceiling fan do I need' is that the size of the ceiling fan you need depends on the size of the room. As a general guideline, you'll want a 36-inch ceiling fan for rooms up to 144 square feet, a 42-inch ceiling fan for rooms 144-225 square feet, and a 52-inch ceiling fan for rooms 225-400 square feet. When choosing a ceiling fan, it's also important to consider the ceiling height and any obstructions like light fixtures or beams.
Ceiling fans come in a variety of sizes, so it's important to measure the room and choose the right size to ensure optimal airflow and energy efficiency. If you're unsure which size to get, it's best to consult with a professional electrician who can assess your specific needs and make a recommendation.