"Cater 2 U" is a four-minute long R&B ballad. According to the sheet music published on the website Musicnotes.com by Sony/ATV Music Publishing, "Cater 2 U" was composed using common time in the key of D major with a slow tempo of 63 beats per minute. The vocal elements span from A3 to B4. Instrumentally it consists of silky synthesizers "slinkand slurp[ing" throughout, creating a seductive feel as stated by Dimitri Ehlrich of "Vibe" and writers of "Billboard" magazine. As the song progresses, it builds to a symphonic crescendo.