How to calculate your GPA (and CGPA)

A grade point average is not a simple average of your grades. It is weighted by credits, which is why one course can move it far more than another.

The method

1. Turn each letter grade into grade points using your scale (on a 4.0 scale, A = 4.0, B = 3.0).
2. Multiply each course's grade points by its credits.
3. Add up those results.
4. Divide by the total number of credits.

GPA = Σ (grade points × credits) ÷ Σ credits

Letter grades as grade points

A common version of the 4.0 scale, with plus and minus grades, looks like this:

Institutions vary in the details — some have no plus or minus grades, some give an A+ extra points — so use the table printed on your own transcript or in your handbook.

A worked example

Four courses in one semester, on a 4.0 scale:

• Biology — 4 credits, A (4.0) → 16.0 points
• History — 3 credits, B+ (3.3) → 9.9 points
• Maths — 4 credits, B (3.0) → 12.0 points
• Art — 2 credits, A− (3.7) → 7.4 points

That is 45.3 points over 13 credits: 45.3 ÷ 13 = a GPA of 3.48. The GPA Calculator does this as you add courses.

Why one course can hurt so much

Credits are weights. A poor grade in a five-credit course carries more than twice the influence of the same grade in a two-credit course — so when you are planning where to put your effort, the big courses matter most.

The example above makes this concrete. Suppose you could improve one grade:

• Raising Art (2 credits) from A− to A adds 0.6 points: 45.9 ÷ 13 = 3.53.
• Raising Maths (4 credits) from B to A adds 4.0 points: 49.3 ÷ 13 = 3.79.

The Maths grade moves the GPA more than six times as far, partly because it has twice the credits and partly because there is more room to improve. When time is short, the course with the most credits and the lowest current grade is where an hour of work pays best.

Which scale?

Use the one your institution publishes. The common scale tops out at 4.0; a 4.3 scale adds an A+ worth 4.3; a 5.0 scale is used where honours or AP courses carry extra weight. If your transcript lists grade points, you can enter those directly.

Schools that use the 5.0 approach often report two figures. The unweighted GPA treats every course the same, so an A is always 4.0. The weighted GPA adds a bonus for harder courses — commonly half a point for honours and a full point for AP or IB — so an A in one of those counts as 4.5 or 5.0. When an application asks for your GPA, check which one it wants; if it does not say, give the figure on your transcript and state the scale.

Pass/fail courses

At most institutions they earn credit but no grade points, so they are left out of both the points and the credits. Mark them as excluded in the calculator and they will not drag your average in either direction.

Failed, repeated and withdrawn courses

• A failed course usually counts in full: zero grade points, but its credits stay in the total you divide by. That is why one F does far more damage than one C.
• A repeated course is handled differently from place to place. Some institutions replace the old grade with the new one; others keep both in the average. The difference can be large, so find out before deciding to retake.
• A withdrawal normally appears on the transcript without affecting the GPA, provided it happens before the deadline. After the deadline it may be recorded as a fail.

From GPA to CGPA

Your cumulative GPA (CGPA) combines every semester so far. It is not the average of your semester GPAs: each semester is weighted by the credits it carried, so a heavy semester counts for more than a light one. The CGPA Calculator does the weighting and can also tell you what GPA next semester needs for you to reach a target. It includes a CGPA-to-percentage estimate using the widely published × 9.5 formula — an approximation, so your institution's own table always takes precedence.

A worked example: a first semester with a GPA of 3.48 over 13 credits, and a second with 3.80 over 17 credits.

(3.48 × 13 + 3.80 × 17) ÷ 30 = 109.84 ÷ 30 = a CGPA of 3.66

Simply averaging the two GPAs would give 3.64. The true figure is higher because the better semester carried more credits.

What do I need next semester?

The same sum runs backwards. Suppose you want a CGPA of 3.70 after a third semester of 15 credits. You will then have 45 credits, so you need 3.70 × 45 = 166.5 points in total. You already have 109.84, so the third semester must supply 56.66 points over 15 credits:

56.66 ÷ 15 = a semester GPA of 3.78

Notice how the target gets harder to move as credits pile up. With 30 credits behind you, one semester can still shift the CGPA noticeably; with 100 behind you, even a perfect semester moves it only slightly. Early semesters set the baseline, which is the strongest argument for taking the first year seriously.

Comparing across systems

There is no universal conversion between a 4.0 GPA, a 10-point CGPA and a percentage. Each institution defines its own, and formulas found online are approximations. If you are applying abroad, send the transcript exactly as issued and let the receiving institution or a credential evaluation service convert it — a self-converted figure can look like an error even when the arithmetic is right.

Working from percentages rather than letters? Start with how to turn a test score into a percentage and a letter grade.