Letter Grade Calculator
Convert an exact percentage or earned-points total into a letter grade using the cutoffs you choose. Start with an editable A-F or plus/minus example, apply your course rounding rule, and audit every grade boundary.
Last updated: August 9, 2026- Direct percentage
- Earned and possible points
- Editable grade bands
- Exact boundary checks
- Target-points planner
Convert a Score to a Letter Grade
Enter one aggregate score and match the editable thresholds to your syllabus. A cutoff belongs to the grade on its row, and every preset is only an example.
Letter grade result
Enter a score, confirm the scale, then calculate.
Target-points result
Calculation steps
- Enter a score, confirm the scale, then calculate.
Your syllabus and official gradebook determine the final cutoffs, rounding policy, curves, and grade.
Automatic copying was blocked. Select the result if needed, then press Ctrl+C on Windows or Command+C on macOS.
| Grade | Minimum, inclusive | Upper boundary | Current result |
|---|
How to Use the Letter Grade Calculator
- Choose Direct percentage when you already know the score, or Earned / possible points when the calculator should divide the points for you.
- Choose a grading-scale example and select Apply Scale Example. Edit every grade label or inclusive minimum needed to match the grading table in your syllabus.
- Keep grade bands in descending order. The first row is the highest grade. The final row starts at 0% and catches every nonnegative score below the cutoff above it.
- Use Exact score for the grade comparison unless your course explicitly rounds or truncates the percentage before applying letter-grade boundaries.
- Select Calculate Letter Grade. Review the exact raw percentage, comparison value, active interval, margin, next cutoff, calculation steps, and full scale audit.
- Optionally select a target letter, fixed points total, and allowed point increment to find the minimum earned points required on that total.
The calculator does not assume one national, university, or high-school grading system. The editable rows are the calculation policy. Check them before trusting the letter result.
Letter Grade Formula and Cutoff Rule
If you enter points, the calculator adds no hidden weighting. It treats the numbers as one aggregate points total and converts the ratio to a percentage.
It then reads the grade bands from top to bottom. Each minimum is inclusive. The first threshold met determines the letter grade. For example, if A starts at 90 and B starts at 80, an exact 90% receives A, while an exact 89.999% receives B when Exact score is active.
This minimum-only model prevents gaps and overlaps. A row does not need a manually entered maximum. Its upper boundary comes from the minimum on the row above it. The last row must start at 0 so every accepted nonnegative percentage has a result.
Example A-F and Plus/Minus Grade Scales
The first example uses ten-point whole-letter bands. The second demonstrates one plus/minus pattern. They are editable reference scales, not universal standards.
| Whole-letter example | Minimum | Plus/minus example | Minimum |
|---|---|---|---|
| A | 90% | A+ | 98% |
| B | 80% | A | 93% |
| C | 70% | A- | 90% |
| D | 60% | B+, B, B- | 87%, 83%, 80% |
| F | 0% | C+, C, C- | 77%, 73%, 70% |
| - | - | D+, D, D- | 67%, 63%, 60% |
| - | - | F | 0% |
Some institutions omit A+, some omit every plus and minus, and others use different cutoffs. A course may also use pass/fail, standards-based levels, a curve, a minimum-exam rule, or another system. Rename the bands when needed, but do not use this tool to force a letter system onto a policy that does not use one.
Worked Letter Grade Examples
Example 1: points to a plus/minus grade
A student earns 174 points out of 200. The exact percentage is 100 x 174 / 200 = 87%. On the example plus/minus scale, B+ begins at 87%, so the result is B+. No display rounding is needed.
Example 2: a score just below a cutoff
Assume A- begins at 90%. An exact score of 89.999% stays below that boundary. With Exact score selected, it receives the next lower band even when a two-decimal display shows about 90.00%. The display is shorter, but the exact comparison has not changed.
Example 3: a nonterminating percentage
One point out of three equals exactly one third of the possible points, or 100/3%. The calculator keeps that rational value internally instead of replacing it with a floating-point approximation. It rounds only the visible decimal according to your display choice.
Exact Boundaries, Rounding, and Truncation
Display precision and grade comparison are separate settings. Display precision changes how many decimal places you see. It does not change the assigned grade. The comparison policy changes the number evaluated against the cutoffs and should match an explicit course rule.
With exact comparison, 89.999% remains below 90%. With half-up comparison to two decimal places, it becomes 90.00% before lookup and may enter the 90% band. With truncation to two places, it becomes 89.99% and remains below. At zero places, half-up sends 89.5% to 90%, while truncation sends it to 89%.
When comparison precision is coarse, a narrow custom band may become unreachable. Suppose one grade starts at 90.04% and the grade below starts at 90.03%, but the policy compares only one decimal place. No one-decimal comparison value fits inside the narrow interval. The calculator blocks that scale and asks you to increase precision or edit the thresholds.
How the Fixed-Total Points Planner Works
The optional planner answers a limited question: how many earned points are required for a target letter grade on a fixed total. It does not add a future exam to current course points. Use the Final Grade Calculator or full Grade Calculator for future-work forecasting.
For exact comparison, the effective target cutoff is the row's entered minimum. A 90% A- threshold on a 200-point total therefore needs exactly 180 points. If only whole points are awarded, a 93% A threshold on a 37-point total needs 34.41 points mathematically and 35 usable points.
The planner rounds upward to the allowed earned-point increment. It never rounds a minimum downward. The increment must divide the fixed total exactly so the set of attainable point totals is unambiguous. When the chosen comparison policy rounds before assigning a letter, the planner derives the lowest raw score that reaches the needed comparison grid, then verifies the usable point result against the same scale.
If you calculate from points and the planner uses the same possible-points total, the result also shows the shortfall from the current earned points. That comparison does not predict what score you need on unfinished work because adding future possible points changes the denominator.
Scores Above 100%, Curves, and Special Rules
Earned points may exceed possible points when extra credit is included. The calculator accepts the result and assigns the highest qualifying band. It does not cap the percentage at 100%. A 110/100 score remains 110%, not 100%. A custom top band may also begin above 100% when the published policy reserves that grade for extra-credit performance.
A curve is different from a fixed cutoff table. If an instructor adds points first, enter the adjusted earned points. If the instructor changes letter cutoffs, edit the scale. If the curve depends on class rank, a distribution, a z-score, or an unpublished decision, this single-score calculator cannot reproduce it.
Minimum-exam rules also sit outside a basic threshold lookup. A course might require at least 50% on the final even when the overall percentage falls in a passing band. Attendance, missing-work limits, competency requirements, academic-integrity penalties, and pass/fail elections can also override the percentage. Confirm these conditions separately.
Letter Grades Versus GPA
A letter grade does not contain one universal GPA value. Institutions assign grade points through their own policy. The University of Illinois Registrar assigns 4.00 to both A+ and A. The University of Alabama catalog assigns 4.33 to A+ while capping the undergraduate cumulative GPA at 4.0. Other institutions omit A+ entirely.
This calculator stops after identifying the letter band. It does not attach a GPA value or combine courses. Use the GPA Calculator with the grade-point map and credit rules published by your school. Keep percentage-to-letter conversion and letter-to-GPA conversion as two separate policy decisions.
Common Letter Grade Calculation Mistakes
- Using an online preset without matching it to the course syllabus.
- Rounding a percentage before lookup when the course uses the exact total.
- Assuming a displayed 90.00% proves the exact score reached 90%.
- Entering a percent sign, comma, fraction, or unit text in a plain-decimal field.
- Putting grade thresholds in ascending order or entering the same cutoff twice.
- Leaving a gap by changing the catch-all row from 0%.
- Capping an extra-credit score at 100% without a policy requiring a cap.
- Treating a letter grade as a universal GPA value.
- Using the fixed-total planner as a future-exam forecast.
- Ignoring curves, minimum-exam rules, or other syllabus conditions.
Related Calculators
Frequently Asked Questions
What letter grade is 90 percent?
It depends on the active scale. In the example A-F scale, 90% is A. In the example plus/minus scales, 90% is A-. Replace the cutoffs with those in your syllabus.
Does 89.5 percent round to an A?
Only when the grading policy rounds to a whole percent before applying a 90% A cutoff. With exact comparison or truncation, 89.5% remains below 90%.
How do I calculate a letter grade from points?
Divide earned points by possible points and multiply by 100. Then compare the exact percentage with the inclusive minimum cutoffs in the active grading scale.
Should I use the exact or displayed percentage?
Use Exact score unless your course explicitly rounds or truncates before assigning letters. Display settings shorten the visible result but do not change the grade.
Can I enter my own letter-grade cutoffs?
Yes. Edit the labels and inclusive minimums, add or remove bands, keep the thresholds strictly descending, and leave the final catch-all threshold at 0%.
Is A+ part of every grading scale?
No. Some institutions use A+, some use plus and minus grades without A+, and some use whole letters only. Choose or edit the scale that your course publishes.
What happens when my score is above 100 percent?
The calculator keeps the full percentage and assigns the highest qualifying band. It does not silently cap extra-credit results at 100%.
Does the letter grade determine my GPA?
No. GPA points, credit weighting, repeated-course rules, and A+ treatment vary by institution. Use the official grade-point map with a separate GPA calculator.
What does the target-points planner calculate?
It finds the minimum earned points needed for a selected letter grade on one fixed possible-points total. It does not forecast a final exam added to current work.
Is this calculated letter grade official?
No. It is an estimate from your score, scale, and comparison settings. Your instructor, syllabus, and official gradebook control the recorded grade.
Calculation Method and Review Basis
The points formula was reviewed against official Montana State University grading guidance. The need for course-specific cutoffs is supported by the University of Memphis Registrar, while the University of Michigan Faculty Handbook states that the university has no single grading scale.
Plus/minus use differs across institutions. Colorado State University makes plus/minus use optional, while the UW-Madison Registrar does not use plus or minus semester grades. The editable whole-letter example was checked against the current Newport News Public Schools program of studies. The A+ plus/minus example was checked against the current Maumee High School handbook, and the no-A+ plus/minus example follows the published UT Austin American Studies scale.
Rounding is also policy-specific. Emmanuel College grading information leaves final-course rounding to faculty. In contrast, South University grading policy documents a half-up rule at .5 unless a syllabus states otherwise. These sources support editable controls; none establishes a universal scale.
Educational planning notice: This calculator does not access your gradebook or determine an official course grade, GPA, academic standing, graduation status, admission, scholarship eligibility, or financial aid. Confirm the result with your instructor or school.