Take a sheet of paper and make three columns. You can also use an Excel spreadsheet. Make headers for each column, Critical Reading, Mathematics and Writing.
Review your SAT answers and count in each section the total number of correct answers. List this under the appropriate heading.
Review your SAT answers again and count in each section the total number of incorrect answers. Unanswered questions are not considered incorrect answers. List the number of incorrect answers under the appropriate heading.
Find out which section is the experimental section and do not include those questions in either the correct answers or the incorrect answers. This section is not included in your score.
Give one point to every correct question answered. Unanswered questions are not listed under correct or incorrect. This is your raw score.
Subtract 1/4th point for every incorrect answer listed under the headings Critical Reading, and Writing. Subtract 1/4th point for every incorrect answer listed under the Mathematic's section except those questions in the grid in section. The grid in questions require the student to produce the answer, meaning there is no multiple choice for these questions. There is no penalty for incorrect grid in questions.
Calculate your raw score by adding the total number of correct answers and subtract the total points for incorrect answers for each section. Remember if the question was not answered it does not count as correct or incorrect.
Locate your per-section raw score on the SAT conversion chart. Add each section together and you have the main SAT score. You will have to wait for the essay to be reviewed and points to be assigned. These points are included in the total for the writing section.