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How to Calculate GPA

A grade-point average summarizes every course grade you've earned into a single number, most often on a 4.0 scale. Colleges, scholarship committees, and academic advisors use it as shorthand for years of coursework, so it's worth understanding exactly how the number is built rather than trusting a vague sense of "my grades are pretty good."

Grade points and the 4.0 / 4.3 scales

Each letter grade maps to a number of grade points. The most common US mapping is A = 4.0, B = 3.0, C = 2.0, D = 1.0, F = 0.0. Schools that use plus/minus grades typically use a finer scale:

• 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

A small number of colleges use a 4.3 scale, where an A+ is worth 4.3 instead of capping at 4.0. This matters mainly for students who earn mostly A+ grades — on a 4.0-capped scale that extra effort doesn't show up numerically, while a 4.3 scale rewards it. Always check your registrar's official scale before comparing your GPA to a published cutoff.

Credit hours

Credit hours measure how much a course counts. A four-credit lab course affects your average twice as much as a two-credit seminar. This is why GPA is a credit-weighted average, not a simple average of grades.

The formula

GPA = Σ(Grade Points × Credits) ÷ Σ(Credits)

Multiply each course's grade points by its credit hours, add those products together, then divide by the total number of credits.

Worked transcript example

Consider a college freshman's fall transcript:

Total quality points = 47.4
Total credits = 14
GPA = 47.4 ÷ 14 = 3.39

Try your own transcript in the GPA Calculator — it handles as many courses as you enter and applies the same formula.

Weighted vs. unweighted GPA (honors and AP courses)

An unweighted GPA caps every course at 4.0, whether it was a study hall or AP Chemistry. A weighted GPA adds bonus points for harder classes — commonly +1.0 for AP/IB courses and +0.5 for honors — so an A in AP Chemistry might count as 5.0 instead of 4.0. A student with all A's in five AP classes could show a 5.0 weighted GPA next to a 4.0 unweighted GPA for the identical letter grades. Most high school transcripts list both numbers; colleges frequently recalculate GPA their own way during admissions review regardless of which number your school reports.

Semester GPA vs. cumulative GPA

A semester GPA applies the formula to just the current term's courses. A cumulative GPA applies the same formula across every term completed so far. A common mistake is averaging semester GPAs directly — that only works if every semester carried identical credit hours, which is rare. Instead, always return to total quality points earned ever divided by total credits attempted ever:

Cumulative GPA = Σ all quality points ÷ Σ all credits attempted

For example, a student with a 3.8 GPA after 15 credits and a 3.2 GPA after 18 credits does not have a 3.5 cumulative GPA. The correct calculation is (3.8 × 15 + 3.2 × 18) ÷ 33 = (57 + 57.6) ÷ 33 ≈ 3.47 — close, but not identical, and the gap grows larger the more the semester credit loads differ.

Transfer credits and pass/fail courses

Transfer credit policies vary widely: some colleges import the credit hours but not the grade, meaning a transferred course affects your credit total toward graduation but not your GPA at the new school. Others recalculate the grade into their own scale. Pass/fail (or credit/no-credit) courses are usually excluded from GPA entirely — they count toward credits needed to graduate but contribute no quality points and no credits to the GPA formula. Because these policies differ by institution, treat any GPA calculator result involving transfer or pass/fail work as an estimate and confirm the details with your registrar.

Common mistakes

• Averaging semester GPAs instead of recombining totals. Always go back to total quality points and total credits.
• Forgetting credit weighting. Treating a 1-credit elective the same as a 4-credit core course skews the result.
• Assuming weighted and unweighted GPA are interchangeable. A 4.3 weighted GPA and a 4.3 on a college's 4.3-max unweighted scale mean very different things.
• Including pass/fail or withdrawn courses in a manual calculation. These typically shouldn't carry grade points at all.

Limitations and edge cases

GPA calculators can't know your school's exact plus/minus values, whether repeated courses replace or average with the original grade, or how your institution rounds the final number (some truncate to two decimals, others round). A retaken course is a particularly common edge case: some schools average both attempts into GPA, others replace the old grade entirely while keeping both on the transcript. Always treat an online GPA calculator as an estimate and verify against your official transcript or registrar policy before making decisions based on a specific number.

FAQ

For grading within a single class rather than across a transcript, see weighted grades explained and how to calculate your final grade.