What does Last Grade Completed mean?

"Last Grade Completed" refers to the highest level of education a person has successfully finished. For example, if someone completed the 12th grade (high school), their last grade completed would be 12. If they attended college and earned a bachelor's degree, their last grade completed might be listed as "16" (representing the typical number of years of education), "Bachelor's Degree," or some other designation depending on the specific application or form.