Grade Calculator

Grade Calculator: Percentage to Letter Grade and Final Grade

Convert between percentage and letter grades, calculate test grades, and find out what grade you need on the final to reach your target. Our free grade calculator supports common grading scales (A–F, 90/80/70/60), points-based inputs, and weighted averages so students and teachers get accurate results without sign-up. Use it alongside our GPA calculator for semester averages and our percentage calculator when you need to work with raw percentages.

What Is a Grade Calculator?

A grade calculator helps you convert numeric scores (percentages or points) to letter grades, or the reverse. It can also compute weighted averages when different assignments count for different percentages of your final grade, and answer questions like: what grade do I need on the final to get a B? Schools and professors use different scales—some use 90–80–70–60 for A–B–C–D, others use 93–85–77–70, or plus/minus systems. Our calculator lets you choose a preset scale or customize the cutoffs so the result matches your syllabus.

Percentage to Letter Grade: Common Scales

In the United States, the most common scale is: A 90–100%, B 80–89%, C 70–79%, D 60–69%, F below 60%. Many schools add plus/minus: A+ 97–100%, A 93–96%, A- 90–92%, and so on. Our grade calculator includes presets for standard (90/80/70/60), strict (93/85/77/70), and pass/fail (e.g. 60% pass). Enter your percentage (or points earned and total points) and the tool shows the corresponding letter grade. If your scale is different, you can set custom cutoffs so the conversion is accurate for your course.

How to Calculate a Test Grade from Points

If you have points earned and total points, your percentage is (earned / total) × 100. For example, 42 out of 50 gives (42/50) × 100 = 84%, which is typically a B. Enter 42 and 50 in the calculator; it will show 84% and the letter grade for your chosen scale. This works for quizzes, exams, or any assignment where the score is given as points. Double-check that you use the correct total (e.g. some tests are out of 40 or 100). Our calculator validates that earned ≤ total and total > 0 so you don't get invalid results.

Weighted Grade Average

When your final grade is made of weighted categories—for example homework 20%, quizzes 30%, midterm 20%, final 30%—you must multiply each category grade by its weight and add them. Formula: Weighted Average = (Grade1 × Weight1 + Grade2 × Weight2 + …) / 100. Example: homework 85% (20%), quizzes 78% (30%), midterm 80% (20%), final unknown (30%). If you want a 80% course grade: 80 = (85×20 + 78×30 + 80×20 + Final×30) / 100. Solving: 8000 = 1700 + 2340 + 1600 + 30×Final, so 30×Final = 2360, Final = 78.67%. Our grade calculator can compute this: enter current grades and weights, then enter desired course grade and final weight to see the grade you need on the final.

What Grade Do I Need on the Final?

This is one of the most common uses of a grade calculator. You have a current grade in the course, the final exam has a certain weight (e.g. 30%), and you want to know what final exam grade you need to get an A, B, or just to pass. The formula is: Required Final = (Desired Course Grade − (Current Grade × (100 − Final Weight) / 100)) / (Final Weight / 100). In words: the part of your grade already determined is Current × (100 − Final Weight) / 100; the rest must come from the final. Our calculator does this for you: enter current grade, final weight, and desired course grade; it shows the minimum final exam grade needed. If it's above 100%, it's impossible; if it's low, you have room to spare.

Final Grade Calculator: Putting It Together

To find your projected final grade: list all assignments and their weights, enter each grade (or leave final as unknown), and the calculator computes the course average. To find what you need on the final: enter all known grades and weights, set desired course grade, and read off the required final exam grade. Use the copy button to save the result. Many students use this before the last exam to see whether they can relax or need to study hard. Teachers can use it to set fair cutoffs and explain to students how final grades are determined.

Different Grading Systems

Besides the standard A–F scale, some schools use numeric grades (0–100), 0–4 scale (like GPA), or narrative evaluations. Our tool focuses on percentage and letter grade conversion and weighted averages; for semester or cumulative GPA across courses, use our GPA calculator. If your school uses a 0–4 scale for individual assignments, you can often map letter grades to numbers (A=4, B=3, etc.) and then use the GPA calculator for the overall average. The grade calculator here is best for single-course percentage and letter grade work and for "grade needed on final" questions.

Accuracy and Fair Use

Our grade calculator uses the math you provide: percentage or points, and the scale you select. The result is as accurate as your inputs and the scale match your syllabus. Always verify cutoffs with your professor—some use 89.5% as A- and others 90%. Weighted averages assume that weights add to 100% and that each category is a single number; if you have multiple homeworks, use their average as the "homework" grade. The "grade needed on final" assumes the final is the only remaining grade; if you have other assignments left, the result is approximate. Use the tool to plan and check; for official grades, rely on your institution's posted policy.

Common Mistakes to Avoid

Using the wrong scale (e.g. 93 cutoff when your school uses 90) gives the wrong letter. Confusing weight with points (e.g. "final is 100 points" vs "final is 30% of grade") leads to wrong "grade needed" calculations—use percentage weights. Forgetting to include all categories in a weighted average undercounts the impact of the final. Entering current grade as a letter instead of percentage can cause errors; convert to percentage first or use a scale that matches. Finally, if the calculator says you need over 100% on the final, it means your current grade is too low to reach the target; you may need to accept a lower course grade or check for extra credit.

Step-by-Step: How to Use Our Grade Calculator

Choose your mode: percentage to letter, points to percentage and letter, weighted average, or grade needed on final. For percentage/points: enter the value(s) and select the grading scale; click Calculate to see the letter grade. For weighted average: add rows for each category, enter grade and weight; the calculator shows the course average. For "grade needed": enter current grade, final weight, and desired course grade; the tool shows the minimum final exam grade. Use presets (e.g. 5 exams, equal weight) to save time. Copy the result for your records. For more education tools, try our GPA calculator and percentage calculator.

Related Tools

GPA Calculator – Grade point average for semester or cumulative. Percentage Calculator – Percent of a number, increase/decrease. Scientific Calculator – General math. Education calculators – Full list.

Conclusion

Our free grade calculator converts percentage to letter grade, handles points-based tests, computes weighted averages, and tells you what grade you need on the final to hit your target. Use the scale that matches your school, enter your numbers, and get instant results. Pair it with our GPA calculator for full picture of your grades and our percentage calculator for any percent-based homework or tests.