# Current 78%, final worth 20%, want 80% — Final Grade Calculator

> You have 78% going into finals worth 20%. You need exactly 88% on the final to finish with an 80% course grade. See your best- and worst-case outcomes.

- **Answer:** Need 88% on the final
- **Category:** Education & Grades
- **Interactive calculator:** https://youcalc.com/en/education-grades/final-grade-calculator/need-on-final-78-want-80/
- **Price:** Free, no sign-up required
- **Full calculator:** [Final Grade Calculator](https://youcalc.com/en/education-grades/final-grade-calculator/)
- **Pre-filled inputs:** `c=78&t=80&w=20`

| Metric | Value |
| --- | --- |
| Current grade | 78% |
| Final weight | 20% |
| Target grade | 80% |
| Required final score | 88% |
| Best possible outcome | 82.4% |
| Minimum guaranteed | 62.4% |


## Overview

With a 78% current grade and a final worth 20% of the course, you need exactly 88% on that exam to land at exactly 80%. The formula is (target − current × 0.80) ÷ 0.20 = (80 − 62.4) ÷ 0.20 = 88. Even if you score 100, the best you can finish is 82.4%; if you score zero, your minimum guaranteed grade is 62.4%.

## Method

The required final score is derived from the weighted-average course grade formula: course grade = current × (1 − w) + final × w, where w = finalWeight / 100. Rearranging to isolate the final exam score gives: required = (target − current × (1 − w)) / w. The best-case course grade assumes a perfect 100 on the final; the worst-case assumes 0. Both are computed from the same formula with the final score substituted in. Sources: RogerHub Final Grade Calculator (https://rogerhub.com/final-grade-calculator/) and Calculator.net Grade Calculator (https://www.calculator.net/grade-calculator.html).

## Related calculators

- [GPA Calculator](https://youcalc.com/en/education-grades/gpa-weighted-grade/)
- [Weighted Grade Calculator](https://youcalc.com/en/education-grades/weighted-grade-calculator/)
- [Grade Percentage to Letter Grade & GPA Calculator](https://youcalc.com/en/education-grades/grade-percentage-letter/)
- [Test Grade Calculator](https://youcalc.com/en/education-grades/test-grade-calculator/)
- [Grade Curve Calculator](https://youcalc.com/en/education-grades/grade-curve-calculator/)
- [Cumulative GPA Calculator](https://youcalc.com/en/education-grades/cumulative-gpa-calculator/)

## Sources

- https://rogerhub.com/final-grade-calculator/
- https://www.calculator.net/grade-calculator.html

---

Interactive version: https://youcalc.com/en/education-grades/final-grade-calculator/need-on-final-78-want-80/ · From YouCalc — https://youcalc.com