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GPA Calculator

Computes a grade point average as the credit-weighted mean of course grade points (quality points divided by total credits), with an unweighted average when credits are omitted, and the nearest US letter grade on the 4.0 scale.

When to use

You have grade points (e.g. A = 4.0, B+ = 3.3) and credit hours for several courses and want the semester or cumulative GPA.

Do not use when: You need the score required on a final exam (use final-grade), or a general weighted mean of other quantities (use weighted-average).

Formula

GPA = Σ(grade_points_i × credits_i) / Σ credits_i; without credits GPA = mean(grade_points)

Uses the common US 4.0 scale mapping (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). Institutions differ on A+ (4.0 or 4.3) and on weighting honours/AP courses; use your school's point values.

Inputs

Parameter	Type	Unit	Required	Description
`grade_points`	number_list		yes	Grade points for each course on your scale, e.g. 4.0 for A, 3.7 for A−, 3.3 for B+, 3.0 for B, 2.0 for C, 1.0 for D, 0 for F.
`credits`	number_list		no	Credit hours for each course, in the same order. Omit for an unweighted average (every course counts once).

Outputs

Output	Type	Unit	Description
`gpa`	number		Σ(grade_points × credits) / Σ credits.
`total_credits`	number	credits	Sum of credits (number of courses when credits are omitted).
`total_quality_points`	number		Σ(grade_points × credits).
`courses`	integer		Number of courses included.
`letter_grade_equivalent`	string		Letter whose standard 4.0-scale value (A 4.0, A− 3.7, B+ 3.3 …) is closest to the GPA; only returned when all grade points are ≤ 4.3.

Example

A, A−, B+, A with 3, 4, 3, 3 credits: {"grade_points":[4,3.7,3.3,4],"credits":[3,4,3,3]} → {"gpa":3.75,"total_credits":13,"total_quality_points":48.7,"courses":4,"letter_grade_equivalent":"A-"}

Unweighted: 3.0, 2.7, 4.0, 3.3: {"grade_points":[3,2.7,4,3.3]} → {"gpa":3.25,"total_credits":4,"total_quality_points":13,"courses":4,"letter_grade_equivalent":"B+"}

GET https://tttkmbb.com/api/v1/calculate/gpa?grade_points=4%2C3.7%2C3.3%2C4&credits=3%2C4%2C3%2C3

Machine access

API: GET https://tttkmbb.com/api/v1/calculate/gpa (query parameters) or POST with a JSON body {"inputs": {...}}
Schema: https://tttkmbb.com/api/v1/calculators/gpa · Markdown: https://tttkmbb.com/everyday/gpa.md · JSON definition: https://tttkmbb.com/everyday/gpa.json
MCP: server https://tttkmbb.com/mcp, tool run_calculator with calculator_id="gpa"
OpenAPI operationId: calculate_gpa
Freshness: static. Authentication: none. Rate limit: fair use (see rate limits).

Sources

College Board – How to Convert Your GPA to a 4.0 Scale (reference)
Academic grading in the United States (Wikipedia) (reference)

FAQ

How do I combine a previous cumulative GPA with new courses?

Enter the old GPA as one 'course' with grade_points = old GPA and credits = total credits already completed, then add the new courses.

Do pass/fail or withdrawn courses count?

Usually not: they carry no grade points and are excluded from both quality points and credits. Leave them out.

Related calculators

Final Grade Calculator — Score needed on a final exam to reach a target course grade.
Weighted Average Calculator — General weighted mean of any values.