Gpakit

This is a reference site for the arithmetic behind high school and college life. Weighted GPA, unweighted GPA, what you need on your final, SAT-to-ACT concordance, 529 growth projection — thirty-five calculators in all, and a dozen explainer posts that show the formula behind each one. Every tool here is one you could reproduce on a napkin once you know the inputs, and the site exists because that napkin work is usually faster and more honest than the search results above it. Nothing here is paywalled, nothing here tracks you beyond the advertising disclosed in the privacy policy, and nothing here personalizes. We do the math; the decisions are yours.

College Acceptance Probability Estimator
College & Admissions
Dean's List GPA Threshold Calculator
College & Admissions
Financial Aid Gap Calculator
College & Admissions
529 Plan Growth Calculator
College & Admissions
Merit Scholarship Estimator
College & Admissions
Transfer GPA Scale Converter
College & Admissions
ACT to SAT Converter
Exams & Scores
AP Exam Score Predictor
Exams & Scores
Grade Curve Calculator
Exams & Scores
Weighted Exam Average Calculator
Exams & Scores
Final Exam Grade Needed Calculator
Exams & Scores
SAT to ACT Converter
Exams & Scores
Test Score Drop Calculator
Exams & Scores
Class Rank Percentile Calculator
GPA & Grades
Cumulative GPA Calculator
GPA & Grades
GPA to Letter Grade Converter
GPA & Grades
Grade Needed to Pass Calculator
GPA & Grades
Grade Point Scale Reference
GPA & Grades
Honors Threshold Calculator
GPA & Grades
Pass/Fail GPA Impact Calculator
GPA & Grades
Semester GPA Calculator
GPA & Grades
Unweighted GPA Calculator
GPA & Grades
Weighted GPA Calculator
GPA & Grades
Radioactive Half-Life Calculator
Math & Science Tools
Quadratic Equation Solver
Math & Science Tools
Scientific Notation Converter
Math & Science Tools
Significant Figures Calculator
Math & Science Tools
Assignment Deadline Prioritizer
Study & Learning
Flashcard Review Date Calculator
Study & Learning
Pomodoro Session Planner
Study & Learning
Reading Time Estimator
Study & Learning
Spaced Repetition Interval Calculator (SM-2)
Study & Learning
Study Break Duration Calculator
Study & Learning
Study Hours per Credit Calculator
Study & Learning
Weekly Study Load Calculator
Study & Learning

Most-used tools, if you need a starting point

These are the calculators readers land on most often — a mix of grade math, exam math, and admissions math that together cover the questions we see in our inbox week after week.

What's on Gpakit

Calculators

Thirty-five tools across GPA and grades, exam scoring, study planning, college admissions math, and the academic-arithmetic odds and ends that keep showing up on homework. Browse all →

Explainer posts

A dozen explainer posts that walk through the math behind the tools — how GPA is actually calculated, what the SAT-ACT concordance table is doing under the hood, why the Pomodoro 25-minute block is neither arbitrary nor magic. Read the blog →

Sources & accuracy

Every formula traces to a primary source and every limitation is stated on the page. We do not invent rules, and we do not personalize. More about our method →

From the blog

Recent explainers from the blog

How we build these calculators

Every calculator on this site traces to a public, documented source — a registrar's handbook, a College Board PDF, a peer-reviewed paper, or a standard accreditation convention. When a tool extrapolates beyond that source (the AP score predictor, which depends on annually shifting cutoffs, is the clearest example), we say so in plain language on the page itself rather than tuck it into a footnote. The formula each calculator uses is printed in the explanatory prose below the form, not hidden inside JavaScript. Weighted GPA adds the standard +1.0 for AP and +0.5 for Honours, but your school's policy may differ; we flag that and link to the common variations where it matters. When a published rule changes — AP cutoff shifts, FAFSA Student Aid Index rules, 529 rollover provisions — we update the affected pages and note the revision in a short changelog. Readers email corrections regularly, and several of the calculators here exist in their current form because of those emails.