Letter Grade Calculator - Free Online Tool

Convert scores to letter grades, GPA, and weighted averages

Whether you are a student tracking your progress across multiple assignments, a teacher quickly grading a stack of tests, or a parent monitoring your child's performance, our Letter Grade Calculator covers every scenario in one place. Simply enter your scores and weights to get an instant letter grade, GPA equivalent, and weighted course average — no math required. The calculator operates in three modes. The Weighted Grades mode accepts individual assignment scores (as percentages, letter grades, or raw points) along with their weights to compute your overall course grade. You can add as many rows as you need, enable extra credit, and even drop your lowest score to reflect common grading policies. The EZ Grader mode is designed for teachers: enter the total number of questions and the number of wrong answers, and the tool instantly converts that into a percentage and letter grade. It can also display a full grading chart showing every possible wrong-answer count with its corresponding grade. The Final Exam Planner answers the classic question: 'What score do I need on my final exam to get an A?' Enter your current grade, the final's weight, and your goal, and the calculator tells you exactly what you need — with a warning if the target is mathematically out of reach. All three modes use the standard US grading scale: A+ (97–100%), A (93–96%), A- (90–92%), B+ (87–89%), B (83–86%), B- (80–82%), C+ (77–79%), C (73–76%), C- (70–72%), D+ (67–69%), D (63–66%), D- (60–62%), and F (0–59%). Every letter grade is paired with its GPA equivalent on the 4.33 scale, from A+ = 4.3 down to F = 0.0, matching the scale used by many colleges and universities. The weighted average formula is straightforward: multiply each assignment's score by its weight, sum those products, then divide by the total weight. This approach works whether you assign percentage weights (like 30% for a midterm) or point weights (like 100 points for an essay). If weights are not entered, the calculator treats every row equally and computes a simple average. The tool also highlights how much unallocated weight remains, so you can ensure your entries add up to 100% before finalising your grade estimate. Designed for students of all levels — from middle school through graduate school — and for educators who need a quick grading tool in the classroom, this calculator removes the friction from grade tracking. Auto-calculation means you see results the moment you type, so you can experiment with different scenarios: 'What happens if I score 95% on the final versus 80%?' or 'If I drop my lowest quiz grade, does that push me into the B+ range?' The visual grade bar and per-assignment breakdown chart make it easy to see which assignments are weighing your grade down and where you have room to improve.

Understanding Letter Grades and GPA

What Is a Letter Grade?

A letter grade is a shorthand way to communicate academic performance on a standardised scale. In the United States, the most common system runs from A+ (the highest) through F (failing), with plus and minus modifiers adding granularity. Each letter corresponds to a percentage range: A+ covers 97–100%, A covers 93–96%, and so on. Most institutions also map letter grades to a GPA (Grade Point Average) scale, typically 4.0 or 4.33, where A+ equals 4.3, A equals 4.0, and F equals 0.0. Colleges use cumulative GPA to assess academic standing, scholarship eligibility, and graduate school admissions. Understanding exactly where you stand on the letter grade scale helps you set realistic targets for the rest of the semester.

How Is a Weighted Grade Calculated?

A weighted grade accounts for the fact that not all assignments carry equal importance. The formula is: Weighted Grade = (sum of score × weight) ÷ (sum of all weights). For example, if your midterm (worth 40%) scored 88% and your final project (worth 60%) scored 92%, the calculation is (88 × 40 + 92 × 60) ÷ (40 + 60) = (3520 + 5520) ÷ 100 = 90.4%, which maps to an A-. If no weights are provided, each assignment is treated equally and a simple arithmetic mean is computed. When working in points mode, each score is first converted to a percentage (points earned ÷ total points × 100) before being weighted.

Why Letter Grades and GPA Matter

Letter grades and GPA serve several critical functions beyond indicating whether you passed or failed a class. They determine academic probation thresholds, scholarship eligibility, and honour roll status during your studies. For graduate school applicants, undergraduate GPA is typically one of the top two admission factors alongside standardised test scores. Employers in competitive fields often screen for minimum GPA requirements, particularly for early-career roles. Even within a course, understanding your current letter grade and what you need on remaining assignments lets you make strategic decisions — such as whether to prioritise an upcoming paper or to invest more time in exam preparation. The Final Exam Planner feature in this calculator directly supports that kind of informed decision-making.

Limitations and Caveats

This calculator uses the standard US grading scale, which may differ from the grading scale your instructor or institution actually uses. Some professors curve grades, apply participation points that are not captured as a separate category, or use custom thresholds (for example, requiring 95% for an A instead of the standard 93%). Always verify your course syllabus for the exact grading scale in use. Additionally, the GPA equivalents provided here (4.33 scale) may differ from your school's official conversion table — some institutions use a strict 4.0 scale where A+ and A both equal 4.0. The dropped-score feature removes the lowest-scoring rows before calculating, which matches common quiz-drop policies, but be aware that your syllabus may exclude dropped scores only from specific assignment categories.

Letter Grade Formulas

Percentage Grade

Grade % = (Total Points Earned / Maximum Points) × 100

The basic grade calculation divides points earned by the maximum possible points and multiplies by 100 to produce a percentage score.

Weighted Grade Average

Weighted Grade = Σ(Category Weight × Category Score) / Σ(All Weights)

Multiplies each assignment or category score by its weight, sums the products, and divides by the total weight. Works with percentage weights (e.g., 30% midterm) or point weights.

Required Final Exam Score

Required = (Target − Current × (1 − FinalWeight / 100)) / (FinalWeight / 100)

Solves for the minimum final exam score needed to achieve a target overall grade, given the current grade and the final exam's weight as a percentage of the total course grade.

Letter Grade from Percentage

Letter = lookup(Grade %, grading scale thresholds)

Maps a percentage score to a letter grade using defined thresholds. Standard US scale: A = 93–100%, A- = 90–92%, B+ = 87–89%, B = 83–86%, and so on down to F = 0–59%.

Grading Scale Reference Tables

Standard US Grading Scale (with +/- Modifiers)

The most widely used grading scale in US high schools and universities, mapping percentage ranges to letter grades and GPA equivalents on a 4.33 scale.

Letter Grade	Percentage Range	GPA (4.33 Scale)
A+	97–100%	4.3
A	93–96%	4.0
A-	90–92%	3.7
B+	87–89%	3.3
B	83–86%	3.0
B-	80–82%	2.7
C+	77–79%	2.3
C	73–76%	2.0
C-	70–72%	1.7
D+	67–69%	1.3
D	63–66%	1.0
D-	60–62%	0.7
F	0–59%	0.0

International Grade Comparisons

Approximate equivalencies between the US letter grade system and grading systems used in other countries.

US Grade	UK Classification	German Scale	Canadian %	Australian Grade
A+ / A	First Class (70%+)	1.0–1.3	90–100%	HD (High Distinction)
A-	First / Upper 2:1	1.7	85–89%	D (Distinction)
B+	Upper 2:1 (65–69%)	2.0	80–84%	D (Distinction)
B	Lower 2:1 (60–64%)	2.3–2.7	75–79%	C (Credit)
B-	Upper 2:2 (57–59%)	3.0	70–74%	C (Credit)
C+ / C	Lower 2:2 (50–56%)	3.3–3.7	65–69%	P (Pass)
D	Third (40–49%)	4.0	50–64%	P (Pass)
F	Fail (<40%)	5.0	<50%	F (Fail)

Letter Grade Worked Examples

Calculating a Final Grade from 87/100

A student scores 87 out of 100 on a single exam and wants to know the letter grade.

Calculate percentage: 87 / 100 × 100 = 87%

Look up 87% on the standard grading scale

87% falls in the B+ range (87–89%)

GPA equivalent: 3.3 on the 4.33 scale

A score of 87/100 earns a B+ (3.3 GPA). The student is 3 percentage points away from an A- (90%) and 4 points above the B threshold (83%).

Weighted Grade from Homework, Exams, and Projects

A course has three grade categories: Homework (20% weight, score 92%), Midterm Exam (35% weight, score 78%), and Final Project (45% weight, score 88%).

Homework contribution: 92 × 20 = 1,840

Midterm contribution: 78 × 35 = 2,730

Final Project contribution: 88 × 45 = 3,960

Sum of weighted scores: 1,840 + 2,730 + 3,960 = 8,530

Divide by total weight: 8,530 / 100 = 85.3%

85.3% falls in the B range (83–86%), GPA = 3.0

The weighted course grade is 85.3%, which earns a B (3.0 GPA). The midterm exam pulled the average down — if the student had scored 85% on the midterm instead of 78%, the overall grade would rise to 87.75% (B+).

Final Exam Score Needed for an A-

A student has a current course grade of 86% and the final exam is worth 30% of the total grade. They want to achieve an A- (90%) overall.

Apply the formula: Required = (Target − Current × (1 − Weight/100)) / (Weight/100)

Required = (90 − 86 × (1 − 0.30)) / 0.30

Required = (90 − 86 × 0.70) / 0.30

Required = (90 − 60.2) / 0.30

Required = 29.8 / 0.30 = 99.3%

The student needs a 99.3% on the final exam to achieve an A- overall. This is technically possible but very challenging. Realistically, the student should aim for the highest score possible and may need to accept a B+ if the final exam is difficult.

How to Use This Calculator

Select a Calculator Mode

Choose from three tabs: Weighted Grades for calculating your course average across multiple assignments, EZ Grader for quickly converting a test's wrong-answer count to a grade, or Final Exam Planner to find out what score you need on your upcoming final.

Enter Your Scores and Weights

In Weighted Grades mode, type each assignment name, its score (as a percentage, letter grade, or points earned/total), and its weight as a percentage of the total grade. You do not need to make weights sum to 100 — the calculator normalises them automatically. Add extra rows for more assignments.

Review Your Letter Grade and GPA

Results appear automatically as you type. Your overall grade, letter grade (A+ through F), and GPA equivalent on the 4.33 scale are shown instantly. The per-assignment breakdown bars show each item's weighted contribution so you can see which assignments are dragging your grade down.

Use the Final Exam Planner

Switch to the Final Exam Planner tab and enter your current course grade, the exam's weight percentage, and your target overall grade. The calculator tells you exactly what score you need — and flags it as infeasible with a warning if the required score exceeds 100%.

Frequently Asked Questions

How do I calculate a weighted grade average?

A weighted grade average is calculated by multiplying each assignment's score by its weight, summing those products, and dividing by the total weight. For example, if your homework (weight 20%) scored 75%, your midterm (weight 40%) scored 82%, and your final (weight 40%) scored 90%, the weighted average is (75×20 + 82×40 + 90×40) ÷ (20+40+40) = (1500 + 3280 + 3600) ÷ 100 = 83.8%, which is a B. This calculator handles the math instantly — just enter scores and weights in the Weighted Grades tab.

What letter grade is 70%, 75%, 80%, 85%, or 90%?

Using the standard US grading scale: 70–72% is a C-, 73–76% is a C, 77–79% is a C+, 80–82% is a B-, 83–86% is a B, 87–89% is a B+, and 90–92% is an A-. So 70% = C-, 75% = C, 80% = B-, 85% = B, and 90% = A-. Scores at 93% and above reach A territory, with A+ reserved for 97–100%. These thresholds are standard across most US high schools and colleges, but always check your syllabus for any custom cutoffs your instructor might use.

What GPA is an A, B, C, D, or F?

On the 4.33 scale used by many universities: A+ = 4.3, A = 4.0, A- = 3.7, B+ = 3.3, B = 3.0, B- = 2.7, C+ = 2.3, C = 2.0, C- = 1.7, D+ = 1.3, D = 1.0, D- = 0.7, and F = 0.0. Some schools use a strict 4.0 scale where A+ and A both equal 4.0. To calculate your cumulative GPA, multiply each course's GPA value by the number of credit hours, sum those products, and divide by total credit hours. This calculator shows the GPA equivalent for each grade result automatically.

What does the EZ Grader mode do?

The EZ Grader mode is a quick tool for teachers and students to grade a test by counting wrong answers. Enter the total number of questions and the number of answers a student got wrong, and the calculator instantly shows the percentage score and letter grade. You can also enable the full grading chart, which displays every possible wrong-answer count (from 0 to the total) alongside the resulting percentage and letter grade. This is especially useful when grading a class set of papers — you can look up any student's score in seconds.

How do I find out what I need on my final exam?

Use the Final Exam Planner tab. Enter your current overall course grade (the grade you have right now, before the final), the final exam's weight as a percentage of the total course grade, and the target grade you want to achieve overall. The calculator solves for the required final exam score using the formula: Required = (Target − Current × (1 − FinalWeight/100)) ÷ (FinalWeight/100). If the result is over 100%, a warning appears indicating the target is mathematically out of reach. If it is below 0%, you have already secured your target regardless of what you score.

What is the drop-lowest-score feature?

Many courses let students drop their lowest quiz or assignment grade at the end of the semester, which is intended to give some flexibility for a single bad day. The 'Drop Lowest N Scores' field in the Weighted Grades tab lets you simulate this policy. Enter how many of the lowest-scoring rows you want to exclude, and the calculator automatically removes them before computing the weighted average. For example, if you have five quiz grades and your professor drops the lowest one, set this field to 1, and the tool will discard your weakest quiz when calculating your final grade.