Masturbation time is usually not equal to the duration of sex. Masturbation is a solo activity, often focused on quickly reaching orgasm, so it tends to be shorter. In contrast, sex involves interaction between two people, including emotional connection, foreplay, and physical touch, which generally makes it last longer.
Additionally, the emotional state, pace, and needs of both partners during sex can affect its duration.
Therefore, masturbation and sex usually do not have the same duration, and their experiences and purposes differ as well.