A GPA (Grade Point Average) calculator works by first assigning points to each grade you have received in your classes. Here’s a common scale:

• A = 4.0
• B = 3.0
• C = 2.0
• D = 1.0
• F = 0.0

For plus and minus grades, the scale might look like this:

• A+ = 4.0
• A = 4.0
• A- = 3.7
• B+ = 3.3
• B = 3.0
• B- = 2.7
• C+ = 2.3
• C = 2.0
• C- = 1.7
• D+ = 1.3
• D = 1.0
• D- = 0.7
• F = 0.0

The calculator then multiplies these points by the number of credits each course is worth. For example, if you received an A- in a 3-credit class, you would earn 11.1 points for that class (3.7 points * 3 credits = 11.1 points).

Next, the calculator adds up all the points from all your classes. This is your total grade points.

Finally, the calculator divides your total grade points by your total number of credits. This gives you your GPA.

For example, if you earned 46.2 total grade points in 12 total credits, your GPA would be 3.85 (46.2 total grade points / 12 total credits = 3.85 GPA).

Please note that different schools might use slightly different scales, so it’s always a good idea to check with your school to understand their specific scale. Also, some schools use a weighted GPA, which gives more points for honors or AP classes. This explanation is for an unweighted GPA.