Gpakit is a free reference site for the arithmetic behind academic life. Every tool here answers a question a student, parent, or counselor has typed into a search bar: what do I need on my final?, does this AP course actually boost my GPA?, what percentile is rank 12 out of 340?, how fast does a 529 plan really grow? Each one is a single formula rendered into a form that takes your numbers and gives you an answer in the time it would take to open a spreadsheet.
Why we built this
Academic math is mostly public. GPA scales, exam concordance tables, financial-aid formulas, and study-planning heuristics are all documented somewhere — often in a registrar's handbook, a College Board PDF, or a 1987 paper by a Polish cognitive scientist. But "documented somewhere" is not the same as "usable in thirty seconds." Most of the time a student lands on a page, reads three paragraphs of marketing copy, hits a paywall or a login screen, or finds a calculator that works but hides the formula it used. We wrote Gpakit because the formulas deserve to be visible.
Every calculator on this site shows its math. The weighted GPA tool tells you it adds 1.0 to AP courses and 0.5 to Honors courses, and shows both the weighted and unweighted output side by side. The SAT-to-ACT converter uses the College Board's official 2018 concordance table and says so. The 529 growth calculator lays out the future-value-of-annuity formula in the prose below the form. If the formula shifts year to year — AP cutoffs, FAFSA Student Aid Index rules — we flag that too.
Our approach to accuracy
Two commitments drive the content here. First, we do not invent formulas. Every calculator traces to a publicly documented source — a registrar's handbook, a College Board data update, a peer-reviewed psychology paper, or a standard accreditation convention. When a tool extrapolates beyond that source (for example, the AP score predictor, which depends on annually shifting equating cutoffs), we say so in plain language, not buried in a footnote.
Second, we do not personalize. Gpakit does not tell you whether you will get into Stanford, whether your child will qualify for a specific scholarship, or whether your study schedule will work for your particular brain. Those are questions for admissions counselors, financial aid officers, and — honestly — your own judgment. What we do is the math. The acceptance-probability tool gives you a numerical baseline relative to a school's published middle-50% SAT and average GPA. Whether you turn that number into an application strategy is up to you and the people who know your situation.
What's on the site
Thirty-five calculators organized into five categories:
- GPA & Grades — weighted and unweighted GPA, semester and cumulative averages, letter-grade conversion, class rank percentile, grade needed to pass, honors thresholds.
- Exams & Scores — final-exam grade requirements, test-drop impact, SAT↔ACT concordance, weighted exam averages, grade curving, AP score prediction.
- Study & Learning — Pomodoro session planning, SM-2 spaced repetition, reading-speed estimation, flashcard review scheduling, weekly study load.
- College & Admissions — acceptance probability baseline, 529 savings growth, financial aid gap, merit scholarship estimates, transfer GPA conversion.
- Math & Science — significant figures counter, scientific notation converter, quadratic solver with discriminant analysis, radioactive half-life.
Alongside the calculators, the blog publishes explainer posts — how GPA is actually calculated, what the SAT-ACT concordance does and doesn't mean, why the credit-hour study rule has survived a century. These are meant for the reader who wants to understand the formula before trusting it.
Who runs this
Gpakit is an independent publisher. We do not sell tutoring, test prep, admissions consulting, or personalized academic advice. We make no money on any outcome — your grade, your acceptance, your scholarship. Where this site generates revenue, it is through contextual advertising (Google AdSense, disclosed in our privacy policy), never through referral commissions on education products or services.
Get in touch
Spotted an error in a formula, want a calculator added, or noticed a published rule changed? We take corrections seriously — several tools here exist because readers emailed pointing out that the formula we'd written down didn't match the current handbook. Email [email protected].
Nothing on this site is tutoring, counseling, financial advice, legal advice, or medical advice. Always confirm results that affect real decisions — your transcript, your aid package, your credit transfer — with the institution or professional that can authoritatively answer the question for your specific case.