Cumulative GPA:
weight every grade by its credits

How to calculate cumulative GPA

Cumulative GPA is the total of all grade points earned divided by the total credits attempted. Multiply each course grade point by its credit value, add the products, then divide by the sum of the credits. Semesters with more credits count for more.

Why a simple average can mislead

The plain average of 8.0, 7.5 and 8.8 is 8.1, slightly higher than 8.06. The gap appears because the weakest semester, 7.5, carried the most credits. For a small number of semesters the difference is tiny, but it can matter near a cut-off.

A second example on a 4.0 scale: three terms of 15, 16 and 14 credits with GPAs of 3.2, 3.5 and 3.8 give 157.2 grade points over 45 credits, a cumulative GPA of 3.49. The simple average would be 3.5.

The formula also tells you what you need next. Suppose you have 532 grade points over 66 credits and want a cumulative GPA of 8.2 after a further 22-credit semester. You need 8.2 × 88 = 721.6 grade points in total, so the new semester must supply 189.6, which means an SGPA of about 8.62.

Starting from individual courses

If you only have course grades, build one semester at a time. For a semester with courses of 4, 3, 3 and 2 credits and grade points of 9, 8, 7 and 10, the points are 36 + 24 + 21 + 20 = 101 over 12 credits, which is 8.42.

Keep the grade-point total and the credit total from each semester, not just the SGPA. Then you can add them directly without dividing and re-multiplying.

Use a spreadsheet if you have many courses: one column for credits, one for grade points, one for their product. The cumulative figure is then the sum of the product column divided by the sum of the credits column.

Where marks and percentages come in

Some courses report marks, not grade points. The Calcylator score percentage calculator finds the percentage from your score and the total marks, using score ÷ total × 100. Your institution then maps that percentage to a grade point on its own table, so look that up rather than guessing.

Common mistakes

• Averaging semester GPAs without weighting by credits.
• Counting courses that were not graded, such as audits or pass-fail, if your institution excludes them.
• Mixing scales, for example a 10-point semester with a 4-point semester.
• Forgetting repeated courses, which some institutions replace and others average.
• Using rounded SGPA values when exact grade-point totals are available.

Always keep a copy of your institution grade-point table with your calculations. Two institutions can both use a 10-point scale and still give different points for the same letter grade, so a figure that is correct at one place can be wrong at another.