The answer to 'how often to clean carpet' is that most experts recommend having your carpets professionally cleaned every 12-18 months. Regular vacuuming and spot cleaning can help maintain your carpets between professional cleanings, but over time, carpets accumulate dirt, dust, and other pollutants that can only be removed through a thorough deep cleaning.
Factors like the amount of foot traffic, whether you have pets, and whether anyone in your household has allergies may require more frequent professional cleanings, such as every 6-12 months. Carpets in high-traffic areas like hallways and living rooms may also need to be cleaned more often than bedrooms or other low-traffic spaces.