What is a Good STC Rating for Windows A good STC rating for windows depends on how much outside noise you want to reduce. STC measures how effectively a window blocks sound, and higher ratings provide greater noise reduction. While lower ratings offer basic control, homes in busy areas benefit from higher STC levels. Soundproof USA provides high-performance solutions designed for superior sound reduction and long-lasting comfort. For more details visit our website at: https://soundproofusa.com/understanding-stc-ratings/