GPA calculation guide
How GPA Is Calculated: Credits, Grade Points, and the 4.0 Scale
GPA is a credit-weighted average: grade points are multiplied by course credits, those quality points are added, and the total is divided by total credits.
The quick answer
GPA is a credit-weighted average of grade points. In the current Mycelgrid GPA Calculator, each letter grade maps to a base point value, that value is multiplied by the course credits, and the total quality points are divided by the total credits.
Course quality points = course credits x base grade points
Term GPA = sum of course quality points / sum of course credits
That means a higher-credit course affects the GPA more than a lower-credit course. The calculation is not a simple average of the letter grades when course credits differ.
The 4.0-scale map used by this Tool
The current calculator uses this default base grade-point map:
| Letter grade | Base grade points |
|---|---|
| A+ or 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 |
How credits become quality points
Quality points are the intermediate values that make course credits matter. Multiply a course’s base grade points by its credits.
- A in a 3-credit course: 4.0 x 3 = 12.0 quality points.
- B+ in a 3-credit course: 3.3 x 3 = 9.9 quality points.
- A- in a 3-credit course: 3.7 x 3 = 11.1 quality points.
- B in a 3-credit course: 3.0 x 3 = 9.0 quality points.
Those four courses produce 42.0 total quality points across 12 credits. The term GPA is 42.0 / 12 = 3.50.
Why course credits change the result
Credit weighting prevents a 1-credit course and a 4-credit course from having the same influence. For example, a 4-credit A and a 1-credit B produce:
- 4-credit A: 4.0 x 4 = 16.0 quality points.
- 1-credit B: 3.0 x 1 = 3.0 quality points.
- Total: 19.0 quality points across 5 credits.
- GPA: 19.0 / 5 = 3.80.
A simple average of 4.0 and 3.0 would be 3.50, which would not match this credit-weighted model.
How the cumulative planning estimate is combined
When both previous GPA and previous credits are supplied, the Tool combines the previous quality-point estimate with the new term’s base quality points.
Combined GPA = (previous GPA x previous credits + current base quality points) / combined credits
Example: a previous GPA of 3.20 over 60 credits contributes 192.0 estimated quality points. Add the 42.0 quality points from the 12-credit, 3.50 term above and the combined estimate is 234.0 / 72 = 3.25.
This assumes the previous GPA and credits are compatible with the same grading basis. The Tool does not reconcile a different institutional scale or transcript policy.
What this calculation does not determine
The current calculator is a transparent planning model, not an official transcript calculation. It does not decide how your institution treats repeated courses, pass/fail work, transfer credits, grade replacement, local plus/minus rules, or other academic policies.
Review your institution’s grading scale and credit rules before relying on a planning result as an official GPA.
Calculate your GPA
Use the Mycelgrid GPA Calculator to enter course credits and letter grades, optionally add per-course weight bonuses or previous cumulative GPA inputs, and export the current result locally.