How to Calculate Your Grade

Divide the points you earned by the points possible, then multiply by 100:

If you know how many you got wrong instead, subtract first: 3 wrong on a 25-question test is 22 right, and 22 ÷ 25 × 100 = 88%. When questions are worth different points, always use points, not the number of questions.

The most common US scale uses 10-point bands with plus and minus at the edges:

• A: 90–100 (A− 90–92, A 93–96, A+ 97+) → 3.7 to 4.0 GPA points
• B: 80–89 (B− 80–82, B 83–86, B+ 87–89) → 2.7 to 3.3
• C: 70–79 → 1.7 to 2.3
• D: 60–69 → 0.7 to 1.3
• F: below 60 → 0

So 84% is a B (3.0). Some schools use different cut-offs (for example 93% for an A), so your syllabus always takes priority.

Many courses weight categories instead of adding up points. Multiply each category average by its weight, then add:

• Homework 95% × 20% = 19
• Quizzes 80% × 30% = 24
• Tests 78% × 50% = 39

Notice that the strong homework average barely helps: tests count for half the grade. The Average Calculator's weighted mode does this for any number of categories.

Mid-semester, some categories may have no grades yet. Divide by the weights you've actually used, not by 100%. If only homework (20%) and quizzes (30%) are graded:

That's your current grade. It will move as the tests (the other 50%) come in.

Suppose you have 82% now, the final is worth 25%, and you want 85% overall:

1. Your current grade fills the other 75%: 82 × 0.75 = 61.5 points.
2. You still need 85 − 61.5 = 23.5 points.
3. The final is worth 0.25, so you need 23.5 ÷ 0.25 = 94% on it.

In one formula: needed = (target − current × (1 − w)) ÷ w. If the answer is over 100%, the target is out of reach; if it's 0 or less, you've already secured it.

Each question on an n-question test is worth 100 ÷ n percent. For a 25-question test that's 4% each, so:

• Miss 2 → 92% (A−). Miss 3 → 88% (B+).
• For an A (90%), you can miss 10% of the questions, rounded down: 2.5 → 2.
• To pass at 60%, you can miss 40%: 10 questions.

Teachers often call this a grading scale or "e-z grader". The Grade Calculator builds one for any test length.

• Rounding: some teachers round 89.5% to 90% (an A−); others use the exact percent, so 89.5% stays a B+. Ask before the final, not after.
• Extra credit: points above the maximum can push a test over 100%. In a weighted grade they only help the category they're in.
• Dropped scores: if your lowest quiz is dropped, remove it before averaging that category.

Check your answers with the Grade Calculator.

1. 37 out of 40 as a percent and letter grade
   Show answer

   92.5%, A−
2. 18 out of 25
   Show answer

   72%, C−
3. 4 wrong on a 30-question test
   Show answer

   86.67%, B. 26 ÷ 30 × 100.
4. Homework 90% (worth 25%) and tests 76% (worth 75%)
   Show answer

   79.5%, C+. 22.5 + 57.
5. You have 88%, the final is worth 30%, and you want 90%. What do you need?
   Show answer

   94.67%. (90 − 61.6) ÷ 0.3.
6. You have 70%, the final is worth 20%, and you need 60% to pass.
   Show answer

   20%. (60 − 56) ÷ 0.2.
7. How many questions can you miss on a 40-question test and still get 80%?
   Show answer

   8. 20% of 40.
8. You have 75% and the final is worth 25%. What's the best grade you can still get?
   Show answer

   81.25%. 75 × 0.75 + 25.