To turn a score into a grade, divide the points you earned by the points possible and multiply by 100. 22 out of 30 is 73.3%, which is a C on the common 10-point scale (A 90–100, B 80–89, C 70–79, D 60–69, F below 60). The calculator also averages weighted categories and tells you what you need on the final.
How to use this grade calculator
- Choose a mode: a single score (like 22/30), a weighted category average, or the final exam grade you need.
- Score mode: enter points earned and points possible. You get the percentage, letter grade and how far you are from the next letter.
- Weighted mode: enter each category from your syllabus with its weight and your current grade. Add or remove rows to match your class (up to six).
- Final exam mode: enter your current grade, how much the final counts, and the grade you want.
- Pick the letter scale your school uses: 10-point, or plus/minus. Copy the link to save or share the result.
How it's calculated
Percentage from a score
Percent = points earned ÷ points possible × 100. The letter comes from comparing that percentage with the cutoffs of the scale you pick. The calculator does not round, so 89.9% stays a B on a 10-point scale.
Weighted mean calculator
A weighted average gives each category a different share of the final grade. The formula is the standard weighted mean, x̄w = Σ wixi ÷ Σ wi (NIST DATAPLOT Reference Manual, EQ 2-20), where xi is the grade in category i and wi is its weight. It is the same idea OpenStax describes for frequency data: multiply each value by how often (or how heavily) it counts, add, and divide by the total weight.
Because the formula divides by the total weight, your weights don't have to add up to 100. If a category has no grade yet, leave it blank: the calculator skips it and re-scales the rest, which is how most online gradebooks show a running grade mid-term. That makes this mode fit any category-weighted gradebook, including the category-weighted gradebooks many school portals use.
Final exam grade needed
Your course grade after the final is current × (1 − f) + final × f, where f is the final's weight as a decimal. Solve for the final: needed = (target − current × (1 − f)) ÷ f. A result above 100% means the target is out of reach; a result at or below 0 means you've already secured it.
Letter grade scales: schools vary
There is no national US grading scale. The 10-point scale is the most familiar convention, and some states write it into policy. South Carolina's State Board of Education, under S.C. Code § 59-5-68, requires every public school to use A 90–100, B 80–89, C 70–79, D 60–69 and F 0–59. Before 2016 the same state used a 7-point scale: A 93–100, B 85–92, C 77–84, D 70–76, F 0–69. The same score can earn different letters in different places.
The plus/minus option follows the published scale of Northshore School District in Washington, which also lists a GPA value for each letter:
| Letter | Percent (from) | GPA points |
|---|---|---|
| A | 93% | 4.0 |
| A- | 90% | 3.7 |
| B+ | 87% | 3.3 |
| B | 83% | 3.0 |
| B- | 80% | 2.7 |
| C+ | 77% | 2.3 |
| C | 73% | 2.0 |
| C- | 70% | 1.7 |
| D+ | 67% | 1.3 |
| D | 60% | 1.0 |
| F | 0% | 0.0 |
Those GPA values match the quality points the UNC-Chapel Hill registrar uses (A 4.0, A- 3.7, B+ 3.3 down to D 1.0 and F 0.0). Treat them as an example; many high schools add extra points for honors and AP courses. Note that Northshore sets 40% as its lowest recorded grade instead of zero, which this calculator doesn't apply.
Worked examples
What is a 22/30 grade?
22 ÷ 30 = 73.3333, × 100 = 73.3%. That is a C on the 10-point scale and a C on the plus/minus scale. Two more points (24/30) would make it 80%, B.
Weighted categories
Homework 20% at 92, quizzes 20% at 84, tests 50% at 78, participation 10% at 100. Multiply and add: 0.2 × 92 + 0.2 × 84 + 0.5 × 78 + 0.1 × 100 = 84.2%, a B (B with plus/minus). Tests carry half the weight, so they add 39% of the 84.2%. Without the participation grade yet, the running grade is 82.4%, because the other 90% of weight is re-scaled to 100.
Final exam needed
You have 85% going into a final that counts for 20%. For a 90%: (90 − 85 × 0.8) ÷ 0.2 = 110%, so an A isn't possible. For an 80%: (80 − 68) ÷ 0.2 = 60%. For a 70%: 10%, so even a very poor final keeps a C.
X out of Y grade tables
Every score for the most common test and quiz totals, with the percentage, the 10-point letter and the plus/minus letter.
Grades out of 10
| Score | Percent | 10-point | Plus/minus |
|---|---|---|---|
| 10/10 | 100% | A | A |
| 9/10 | 90% | A | A- |
| 8/10 | 80% | B | B- |
| 7/10 | 70% | C | C- |
| 6/10 | 60% | D | D |
| 5/10 | 50% | F | F |
| 4/10 | 40% | F | F |
| 3/10 | 30% | F | F |
| 2/10 | 20% | F | F |
| 1/10 | 10% | F | F |
| 0/10 | 0% | F | F |
Grades out of 15
| Score | Percent | 10-point | Plus/minus |
|---|---|---|---|
| 15/15 | 100% | A | A |
| 14/15 | 93.3% | A | A |
| 13/15 | 86.7% | B | B |
| 12/15 | 80% | B | B- |
| 11/15 | 73.3% | C | C |
| 10/15 | 66.7% | D | D |
| 9/15 | 60% | D | D |
| 8/15 | 53.3% | F | F |
| 7/15 | 46.7% | F | F |
| 6/15 | 40% | F | F |
| 5/15 | 33.3% | F | F |
| 4/15 | 26.7% | F | F |
| 3/15 | 20% | F | F |
| 2/15 | 13.3% | F | F |
| 1/15 | 6.7% | F | F |
| 0/15 | 0% | F | F |
Grades out of 20
| Score | Percent | 10-point | Plus/minus |
|---|---|---|---|
| 20/20 | 100% | A | A |
| 19/20 | 95% | A | A |
| 18/20 | 90% | A | A- |
| 17/20 | 85% | B | B |
| 16/20 | 80% | B | B- |
| 15/20 | 75% | C | C |
| 14/20 | 70% | C | C- |
| 13/20 | 65% | D | D |
| 12/20 | 60% | D | D |
| 11/20 | 55% | F | F |
| 10/20 | 50% | F | F |
| 9/20 | 45% | F | F |
| 8/20 | 40% | F | F |
| 7/20 | 35% | F | F |
| 6/20 | 30% | F | F |
| 5/20 | 25% | F | F |
| 4/20 | 20% | F | F |
| 3/20 | 15% | F | F |
| 2/20 | 10% | F | F |
| 1/20 | 5% | F | F |
| 0/20 | 0% | F | F |
Grades out of 25
| Score | Percent | 10-point | Plus/minus |
|---|---|---|---|
| 25/25 | 100% | A | A |
| 24/25 | 96% | A | A |
| 23/25 | 92% | A | A- |
| 22/25 | 88% | B | B+ |
| 21/25 | 84% | B | B |
| 20/25 | 80% | B | B- |
| 19/25 | 76% | C | C |
| 18/25 | 72% | C | C- |
| 17/25 | 68% | D | D+ |
| 16/25 | 64% | D | D |
| 15/25 | 60% | D | D |
| 14/25 | 56% | F | F |
| 13/25 | 52% | F | F |
| 12/25 | 48% | F | F |
| 11/25 | 44% | F | F |
| 10/25 | 40% | F | F |
| 9/25 | 36% | F | F |
| 8/25 | 32% | F | F |
| 7/25 | 28% | F | F |
| 6/25 | 24% | F | F |
| 5/25 | 20% | F | F |
| 4/25 | 16% | F | F |
| 3/25 | 12% | F | F |
| 2/25 | 8% | F | F |
| 1/25 | 4% | F | F |
| 0/25 | 0% | F | F |
Grades out of 30
| Score | Percent | 10-point | Plus/minus |
|---|---|---|---|
| 30/30 | 100% | A | A |
| 29/30 | 96.7% | A | A |
| 28/30 | 93.3% | A | A |
| 27/30 | 90% | A | A- |
| 26/30 | 86.7% | B | B |
| 25/30 | 83.3% | B | B |
| 24/30 | 80% | B | B- |
| 23/30 | 76.7% | C | C |
| 22/30 | 73.3% | C | C |
| 21/30 | 70% | C | C- |
| 20/30 | 66.7% | D | D |
| 19/30 | 63.3% | D | D |
| 18/30 | 60% | D | D |
| 17/30 | 56.7% | F | F |
| 16/30 | 53.3% | F | F |
| 15/30 | 50% | F | F |
| 14/30 | 46.7% | F | F |
| 13/30 | 43.3% | F | F |
| 12/30 | 40% | F | F |
| 11/30 | 36.7% | F | F |
| 10/30 | 33.3% | F | F |
| 9/30 | 30% | F | F |
| 8/30 | 26.7% | F | F |
| 7/30 | 23.3% | F | F |
| 6/30 | 20% | F | F |
| 5/30 | 16.7% | F | F |
| 4/30 | 13.3% | F | F |
| 3/30 | 10% | F | F |
| 2/30 | 6.7% | F | F |
| 1/30 | 3.3% | F | F |
| 0/30 | 0% | F | F |
Grades out of 40
| Score | Percent | 10-point | Plus/minus |
|---|---|---|---|
| 40/40 | 100% | A | A |
| 39/40 | 97.5% | A | A |
| 38/40 | 95% | A | A |
| 37/40 | 92.5% | A | A- |
| 36/40 | 90% | A | A- |
| 35/40 | 87.5% | B | B+ |
| 34/40 | 85% | B | B |
| 33/40 | 82.5% | B | B- |
| 32/40 | 80% | B | B- |
| 31/40 | 77.5% | C | C+ |
| 30/40 | 75% | C | C |
| 29/40 | 72.5% | C | C- |
| 28/40 | 70% | C | C- |
| 27/40 | 67.5% | D | D+ |
| 26/40 | 65% | D | D |
| 25/40 | 62.5% | D | D |
| 24/40 | 60% | D | D |
| 23/40 | 57.5% | F | F |
| 22/40 | 55% | F | F |
| 21/40 | 52.5% | F | F |
| 20/40 | 50% | F | F |
| 19/40 | 47.5% | F | F |
| 18/40 | 45% | F | F |
| 17/40 | 42.5% | F | F |
| 16/40 | 40% | F | F |
| 15/40 | 37.5% | F | F |
| 14/40 | 35% | F | F |
| 13/40 | 32.5% | F | F |
| 12/40 | 30% | F | F |
| 11/40 | 27.5% | F | F |
| 10/40 | 25% | F | F |
| 9/40 | 22.5% | F | F |
| 8/40 | 20% | F | F |
| 7/40 | 17.5% | F | F |
| 6/40 | 15% | F | F |
| 5/40 | 12.5% | F | F |
| 4/40 | 10% | F | F |
| 3/40 | 7.5% | F | F |
| 2/40 | 5% | F | F |
| 1/40 | 2.5% | F | F |
| 0/40 | 0% | F | F |
Grades out of 50
| Score | Percent | 10-point | Plus/minus |
|---|---|---|---|
| 50/50 | 100% | A | A |
| 49/50 | 98% | A | A |
| 48/50 | 96% | A | A |
| 47/50 | 94% | A | A |
| 46/50 | 92% | A | A- |
| 45/50 | 90% | A | A- |
| 44/50 | 88% | B | B+ |
| 43/50 | 86% | B | B |
| 42/50 | 84% | B | B |
| 41/50 | 82% | B | B- |
| 40/50 | 80% | B | B- |
| 39/50 | 78% | C | C+ |
| 38/50 | 76% | C | C |
| 37/50 | 74% | C | C |
| 36/50 | 72% | C | C- |
| 35/50 | 70% | C | C- |
| 34/50 | 68% | D | D+ |
| 33/50 | 66% | D | D |
| 32/50 | 64% | D | D |
| 31/50 | 62% | D | D |
| 30/50 | 60% | D | D |
| 29/50 | 58% | F | F |
| 28/50 | 56% | F | F |
| 27/50 | 54% | F | F |
| 26/50 | 52% | F | F |
| 25/50 | 50% | F | F |
| 24/50 | 48% | F | F |
| 23/50 | 46% | F | F |
| 22/50 | 44% | F | F |
| 21/50 | 42% | F | F |
| 20/50 | 40% | F | F |
| 19/50 | 38% | F | F |
| 18/50 | 36% | F | F |
| 17/50 | 34% | F | F |
| 16/50 | 32% | F | F |
| 15/50 | 30% | F | F |
| 14/50 | 28% | F | F |
| 13/50 | 26% | F | F |
| 12/50 | 24% | F | F |
| 11/50 | 22% | F | F |
| 10/50 | 20% | F | F |
| 9/50 | 18% | F | F |
| 8/50 | 16% | F | F |
| 7/50 | 14% | F | F |
| 6/50 | 12% | F | F |
| 5/50 | 10% | F | F |
| 4/50 | 8% | F | F |
| 3/50 | 6% | F | F |
| 2/50 | 4% | F | F |
| 1/50 | 2% | F | F |
| 0/50 | 0% | F | F |
Common mistakes
- Averaging the averages. If tests count 50% and homework 20%, a plain mean of your category grades overstates the lighter categories. Use the weights from your syllabus.
- Mixing points-based and weighted grading. Some classes add up all points earned across the term instead of weighting categories. If your syllabus lists points, add them up and use score mode with the grand totals.
- Assuming rounding. Whether 89.5% becomes an A is a teacher or school decision. Plan for the cutoff, not the rounded one.
- Using the wrong current grade for the final. The final-needed formula wants your grade across everything except the final, which is usually what the gradebook shows before the exam.
- Forgetting extra credit or dropped scores. Dropped lowest quizzes or extra credit change the category grade; enter the category grade your gradebook shows after those rules.
Class grades vs AP exam scores
Your course letter grade and your AP exam score are separate. The AP exam is scored 1–5 by College Board, independent of what your teacher records. To estimate an exam score, try the AP Statistics score calculator or any of the others: APUSH Score, AP World History Score, AP Chem Score, AP Bio Score, AP Physics 1 Score, AP Lang Score.
Frequently asked questions
What is a 22/30 grade?
22 out of 30 is 73.3%. On the common 10-point scale (A 90–100, B 80–89, C 70–79, D 60–69) that is a C; on a plus/minus scale like Northshore School District's it is a C.
What is a 26/30, 27/30 or 23/30 grade?
26/30 is 86.7%, B. 27/30 is 90%, A. 23/30 is 76.7%, C. Letters use the 10-point scale; your school's cutoffs may differ.
What is a 20/25 grade?
20 out of 25 is 80%, B on a 10-point scale. With plus/minus grades it is a B-.
23 out of 25 as a percentage?
23 ÷ 25 × 100 = 92%, an A on a 10-point scale and an A- on the Northshore plus/minus scale.
11 out of 15 is what percentage?
11 ÷ 15 × 100 = 73.3%, which is a C on a 10-point scale.
35 out of 40 as a percentage?
35 ÷ 40 × 100 = 87.5%. That is a B on a 10-point scale and a B+ with plus/minus grades.
What is a 16/20, 32/40 or 17/25 grade?
16/20 and 32/40 are both 80%, a B (B- with plus/minus). 17/25 is 68%, D.
What letter grade is a 2.5 GPA?
A 2.5 GPA is not a single letter. On the UNC-Chapel Hill registrar's 4.0 scale a C+ is worth 2.3 and a B- is 2.7, so a 2.5 average sits between them: roughly a C+/B- average. High schools that weight honors or AP courses count differently.
How do I calculate a weighted grade?
Multiply each category's grade by its weight, add the results and divide by the total weight. With homework 20% at 92, quizzes 20% at 84, tests 50% at 78 and participation 10% at 100, the weighted grade is 84.2%.
What do I need on my final to get an A?
Required final = (target − current × (1 − final weight)) ÷ final weight. With an 85% grade and a final worth 20%, a 90% A needs 110%, which is above 100% and not possible; an 80% B needs 60%.
Is there a standard US grading scale?
No. Grading scales are set by states, districts, schools or individual teachers. Some states set one by law or policy: South Carolina's State Board of Education requires A 90–100, B 80–89, C 70–79, D 60–69 and F 0–59 in its public schools. Before 2016 South Carolina used a 7-point scale with A starting at 93.
Does 89.5% round up to an A?
It depends on your teacher or school. This calculator does not round: 89.5% is a B on a 10-point scale. Northshore School District's published scale, for example, lists B+ as 87–89.9%, which means no rounding up to the next letter.
Sources & method
- South Carolina State Board of Education — Uniform Grading Policy (10-point scale, 2019)
- Northshore School District (WA) — Grading policy (plus/minus scale and GPA values)
- UNC-Chapel Hill Office of the University Registrar — Explanation of grading system (quality points)
- NIST DATAPLOT Reference Manual — Weighted mean (formula EQ 2-20)
- OpenStax Introductory Statistics 2e — 2.5 Measures of the center of the data
Results are estimates for general information. Found an error? It helps everyone — see our methodology.