The assumptions behind every calculator result.

Scope

The homepage planner and six dedicated calculators cover four calculation families: credit-weighted GPA, equal-credit GPA, cumulative GPA, and weighted course grades. The homepage and weighted GPA calculator use a traditional 4.0 base table with one example rigor-bonus model. All tools are intended for transparent what-if planning, not for reproducing every US school policy.

The high school GPA calculator uses base grade points without course-level bonuses. The cumulative calculator combines existing quality points with valid new-course rows. The GPA-without-credits tool averages grade points only when every class counts equally. The semester and weighted-grade tools use percentage weights rather than course credits.

Base grade-point table

The current planner does not offer D- as an input. A school using 3.67 instead of 3.7 or another plus/minus table can produce a different result.

Course-level weighting

Weighted grade points are capped at 5.0 per course. The same demonstration bonus is applied to the selected grade, including an F. This is a transparent software rule, not a claim that a school awards rigor points to every failing grade. Visitors must compare the model with the school handbook.

Published formulas

Course credits determine influence in the credit-weighted tools. A one-credit course contributes twice as much as a 0.5-credit course.

Input validation

A course-credit value is valid only when it is numeric, from 0.5 through 10 inclusive, and aligned to a 0.5-credit step. Blank values, 0.3, 10.5, and 99999 are invalid. An invalid course row is excluded while every valid row continues to contribute, and the result panel reports the exclusion.

The cumulative calculator accepts a current GPA from 0 to 5 and nonnegative completed credits; the 10-credit limit applies to each new course, not to the completed-credit total. The semester calculator accepts grades and weights from 0 to 100 and requires its three weights to total 100. The category-weight calculator accepts scores from 0 to 200, weights from 0 to 100, and labels a partial-weight result as normalized rather than final.

Course names are labels only. They do not affect the result and should not contain student IDs or sensitive records.

Precision and rounding

The calculators use JavaScript numeric precision and keep the unrounded quotient until display. GPA and quality-point results are displayed with two decimal places using US number formatting. Credits are displayed with up to one decimal place, and course-grade tools display the precision stated in their result panels.

This display rounds to the nearest shown value. Some institutions truncate, retain three decimals, or round individual course products. A transcript can therefore differ by 0.01 even when the same visible inputs are used.

Published validation cases

The default-plan result can be reproduced as weighted quality points of 3.7 + 4.3 + 4.5 + 3.0 = 15.5, then 15.5 ÷ 4 = 3.875, displayed as 3.88. These cases are also covered by automated tests in the site repository.

Scenario storage

Plan A, an optional Plan B, the active plan, course labels, grades, levels, and credits are serialized to browser localStorage under gradehorizon-planner-v2. The site does not require an account or server-side save.

When an earlier saved plan is found, the planner copies it to the current storage version before removing the legacy key. The Reset planner action replaces both plans with the published four-course sample. Removing the only remaining course replaces it with a blank course row so the interface remains usable.

Source hierarchy

1. The visitor's current school handbook, transcript key, syllabus, or registrar policy.
2. The current official organization guide for specialized calculations such as AAMC, LSAC, NCAA, or College Board.
3. GradeHorizon worked examples and explanatory articles.
4. General conventions only when no controlling policy is available.

GradeHorizon links to the controlling source near specialized claims. A source is not copied as a substitute for original explanation.

Update and correction process

Calculator logic is reviewed when the interface, grade table, validation rule, or rounding behavior changes. Policy articles are reviewed when an official source announces a relevant change or a reader reports a conflict.

To request a correction, send the page URL, inputs, displayed result, expected result, and supporting official source to hello@gradehorizon.com. Arithmetic corrections are reproduced before publication. Policy corrections are checked against the organization that controls the rule.