Single Grade GPA Impact Calculator
Calculate how a single grade changes your cumulative GPA from current GPA, credits earned, and new course hours.
Returns new GPA for each letter grade A-F.
Understanding how a single grade affects your overall GPA helps you prioritize your efforts. A B in a 4-credit course has more impact than an A in a 1-credit course — this calculator quantifies exactly how much any single grade will move your GPA.
How GPA is calculated: GPA = Sum of (Grade Points × Credit Hours) / Total Credit Hours Attempted
Grade points on the standard 4.0 scale:
- A+ = 4.0 (some schools: 4.3)
- 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
- F = 0.0
The impact formula: New GPA = (Current GPA × Current Credits + New Grade Points × New Course Credits) / (Current Credits + New Course Credits)
Example: Current GPA: 3.2 over 45 credits New course: 3 credits, grade B (3.0 points) New GPA = (3.2 × 45 + 3.0 × 3) / (45 + 3) = (144 + 9) / 48 = 153 / 48 = 3.1875 ≈ 3.19
Key insight: The more credits you’ve already accumulated, the smaller the impact of any single course. If you have 120 credits completed and add one 3-credit course, that course represents only 2.4% of your total credits — it can only move your GPA by a small amount in either direction. Conversely, early in your academic career, each course matters more.
What GPA do you need? This calculator also helps you figure out what grade you need in the current course to achieve a specific target GPA.
How we build and check this calculator
This calculator runs entirely in your browser, so the numbers you enter stay on your device. The math behind it is written by hand and tested against worked examples and standard references before the page goes live.
SuperGlobalCalculator is independently built and maintained. See how we build and verify our calculators.