Vanity size has been a common practice in retail and has a big impact on customers. The practice of employing clothing labels that are smaller than the actual objects is known as vanity sizing; it has become increasingly common among clothing manufacturers. Body image is more than just a reflection of the outside world in a mirror. The body notion is extremely subjective and influenced by one’s surroundings, even though it contains objective physical features. Its contents can also be interpreted positively or negatively. This study aims to measure the level of mental workload on online consumers due to Vanity sizing. The authors followed a quantitative research design and conducted a Questionnaire study of around 156 respondents. The study involved students from IIM Mumbai, India, as well as LinkedIn Connections of Author Profile. Compared to students who are not majoring in clothing, textiles, and merchandising, it’s probable that these people have a greater knowledge of manipulated clothing sizes or vanity sizing. The Respondents are Online shopping consumers. The data collected were analyzed by conducting two studies. Study 1 was described as a questionnaire study and study 2 was described as measuring mental workload by the “NASA TLX” method. It was a novel study for consumers to reduce misperceptions regarding vanity sizing.