Methodology
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How Our Tools Are Built.
This page describes how the Final Grade Calculator, the tool published today, reaches its answer, what it assumes and how it handles unusual input. Other tools will be documented here as they are published.
Formula And Method
Required final score = (target × 100 − current × (100 − final weight)) ÷ final weight. The tool also shows the course grade you would finish with at 0% and at 100% on the final. Values are kept at full precision until the result is displayed.
Validation
Entries must be complete numbers such as 88 or 88.5, with an optional % sign. Text such as 88abc, negative numbers and grades above 100% are rejected with a message. The final exam weight must be above 0 and no more than 100, and cannot be a letter. In the tracker, every filled row needs a valid grade and weight, and the weights must add up to 100% minus the final exam weight before the result is used.
Testing
On October 4, 2026 the calculator was checked against worked examples: 88, 90 and 40 gives 93%; 50, 90 and 40 gives 150% (maximum overall grade 70%); 88, 60 and 40 gives 18%; 90, 60 and 20 gives −60% (target already met); 75, 60 and 20 gives 0%; 88, 90 and 100 gives 90%. Decimal values, blank fields, zero and excessive weights, letters and malformed text, and keyboard submission were also tested. Tests are repeated when a formula or its wording changes.
Stated Assumptions
Your current grade must cover all non-final coursework and the final must be the only remaining component. The exam is capped at 100% and extra credit is not applied. Letters use a common scale (A = 93, A− = 90, B+ = 87, B = 83 and so on). A target letter uses the minimum for that letter, and a current letter is an estimate at the middle of its range. Schools use different scales, so check yours.
Sources
The weighted-average formula is standard arithmetic rather than a published standard, and the letter scale is a common convention rather than an official one. No external dataset is used. If a future tool relies on an external source, it will be cited on that tool page.
Rounding And Review
Required scores are rounded up to the next 0.1% so the displayed figure is never lower than the exact requirement, and achievable grades are rounded down to 0.1%. The exact value is also shown. Tool pages show when they were last reviewed. There is no fixed review schedule yet; a tool is re-checked whenever its formula or wording changes.
About Our Methods.
Short answers about how our tools are built and checked.
Where can I see the formula a tool uses?
Each tool page includes a section explaining the formula or method. The Final Grade Calculator, for example, shows its formula and a worked example.
What if a result does not match my school's rules?
Grading scales and rounding differ between schools. Tools state their assumptions so you can see where your own rules may differ, and you should check with your instructor.
What happens if I find an error?
Please tell us through the contact page. Confirmed errors are corrected as soon as practical and the page’s review date is updated.
How often are tools reviewed?
Tools and their explanations are reviewed from time to time, and each tool page shows when it was last reviewed.
Found An Error? Tell Us.
Last updated: October 4, 2026