To some high school seniors, the thought of continuing school for another four years to earn a bachelor's degree seems overwhelming. Plus, the costs for tuition, fees, room and board can become very expensive. However, income data strongly supports the fact that a bachelor's degree offers greater lifetime earning potential than a high school diploma.

Diploma Versus Bachelor's Degree

The difference in income for a typical high school graduate and a person who holds a bachelor's degree was more than $400 per week in 2012, according to the Bureau of Labor Statistics. The median weekly wage for someone with a diploma was $652, while the median weekly income for someone with a bachelor's degree was $1,066. This amounts to a difference of roughly $1,800 per month and roughly $21,500 per year.

Diploma Versus Other Degrees

The earnings differential between a person who has a high school diploma and a person who holds another degree is significant as well. For persons with some college but no degree, the median weekly income was $727 in 2012, according to the Bureau of Labor Statistics, compared to $652 for diploma holders. With an associate's degree, the median weekly income rose to $785. Thus, a two-year degree contributed to a $133 weekly difference compared to those who hold only a high school diploma, or nearly $7,000 per year. Advanced degrees showed much higher earning potential. With a master's degree, median weekly income was $1,300. A doctoral degree netted $1,624 per week, and a professional degree showed a median weekly income of $1,735.

Trends

The value of a bachelor's degree relative to a high school diploma has increased since the mid-1990s. The National Center for Education Statistics (NCES) noted this trend in a study of 25- to 34-year-old workers from 1995 to 2010. In 2010, the study showed that with a bachelor's degree, the median income was $45,000 -- virtually the same as the median income with a bachelor's degree in 1995. The median income with a diploma in 2010 was $29,900 -- slightly lower than in 1995, following a few years of economic hardship.

Gender

Gender also plays a role in the income gap, according to NCES data. Not only did men still earn more than women in 2010, but the diploma-to-bachelor's-degree differential was greater. Women ages 25 to 34 with a high school diploma earned a median income of $25,000 in 2010. With a bachelor's degree, they earned $40,000 -- a $15,000 difference. In 2010, men with a high school diploma earned a median annual income of $32,800. With a bachelor's degree, their median income was $49,800 -- a $17,000 difference.