Grade Calculator

How grades are calculated

Nearly every grade comes from the same two ideas: turning scores into a percentage, and turning that percentage into a grade. What differs between courses is whether all marks count equally, and where the boundaries between grades sit. This calculator handles both, and shows its working so you can compare the result with your course rules.

If your school gives whole-number marks on a points scale (2 to 5, 1 to 10) rather than percentages, the grade average calculator is built for that system.

Grading by total points

When every mark counts the same, add the points you earned and divide by the points available. Scores of 18/20, 42/50 and 71/100 give 131 of 170 points, which is 77.06%. Leave the weight fields empty for this method.

Weighted grades

Many courses give each category a share of the final grade instead. Suppose homework is worth 20%, the midterm 30% and the final exam 50%, and you scored 90%, 75% and 82%. The weighted grade is (90 × 20 + 75 × 30 + 82 × 50) ÷ 100 = 81.5%. The same scores averaged without weights would give 82.33%, which is why using the right method matters.

If the weights you enter add up to less than 100% — because the final exam has not happened yet, for example — the calculator divides by the weight you have entered. The result is then your grade on the work completed so far, and the page says so.

What do I need on the final exam?

This page works out the grade you have from the scores you enter. The opposite question — what the final has to be for the course to end at a target — has its own final grade calculator, which takes your current grade and the final’s weight and shows the score needed for every letter grade.

Grading scales

There is no universal grading scale. A 90% may be an A in one school, a 1 or a 10 in another, and a distinction somewhere else, and the boundaries often differ between courses in the same school. The four presets are only starting points:

Preset grading scales. All minimums and labels can be edited after loading a preset.

Preset	Bands
Letter grades A–F	A 90, B 80, C 70, D 60, F below 60
Letter grades with + and −	13 bands from A+ at 97 down to F below 60, each 3 or 4 points wide
10-point scale	10 at 90, 9 at 80, 8 at 70, 7 at 60, 6 at 50, 5 at 40, Fail below 40
Pass / fail	Pass at 50, Fail below

Choosing a preset replaces every row in the table above it; editing any minimum or label afterwards switches the dropdown to “Custom” so your own scale is not overwritten. Up to 20 grade rows are allowed. A percentage earns the highest grade whose minimum it reaches — a 97% on the letter scale with plus and minus reaches the A+ band at 97, not the A band at 93, because bands are checked from the top down.

Worked example: a full course

Take a course with four items: a homework average of 88/100 worth 15%, a midterm of 76/100 worth 25%, a lab portfolio of 45/50 worth 20%, and a final exam of 81/100 worth 40%. Each item’s own percentage is homework 88%, midterm 76%, lab 90%, final 81%. The weighted total is (88 × 15 + 76 × 25 + 90 × 20 + 81 × 40) ÷ 100 = (1,320 + 1,900 + 1,800 + 3,240) ÷ 100 = 82.6%. The weights add up to 100, so nothing is scaled. On the default letter scale, 82.6% is at least 80 and below 90, so the grade is B.

Reading the result

The headline is the overall percentage the grade is based on — the weighted percentage when every item has a weight, or the points percentage otherwise. Below it, “Total points” is the raw sum of scores over the raw sum of maximums, which the calculator always shows even in weighted mode, so a heavily-weighted low score and a lightly-weighted high score can be told apart. The item-by-item table lists every entry’s own percentage and, in weighted mode, its weight and its contribution to the final percentage — score percentage multiplied by weight, divided by the total weight entered.

Edge cases

• Mixing weighted and unweighted items. Weights are all-or-nothing: if some items have a weight and others do not, the calculator flags the ones missing a weight rather than guessing what they should count for.
• Weights that do not add up to 100. The calculator divides by whatever total you entered, so a 60%-weighted partial course still returns a valid percentage — your grade on the work covered so far — and a note says the weights are not 100.
• A score above its maximum. Extra credit is allowed and counted as entered; the result notes when at least one item scored above its maximum.
• A percentage below every band. If the lowest band in the scale has a minimum above 0 and the result falls under it, the grade shows as “Below every band” rather than picking the nearest one.
• Blank rows. A row with nothing entered in it is skipped rather than treated as a zero, so a spare row left over from removing an item does not drag the grade down.

Common mistakes

• Averaging percentages when the course is weighted. A simple average treats every item the same regardless of how much it counts; see the 81.5% vs 82.33% example above for how far that can be off.
• Forgetting a category still to come. Entering only the items graded so far and setting their weights to add up to 100 gives a grade as if the missing work counted for nothing. Leave the weights at their real course share instead, and the calculator will show the note about a partial total.
• Using the wrong maximum for a percentage-graded item. If a piece of work is already marked as a percentage, enter it as the score with 100 as the maximum, not as the score with the raw mark-scheme total.

Getting an accurate result

• Use your syllabus or course handbook for weights and grade boundaries.
• Enter items exactly as marked. For work graded as a percentage, use the percentage as the score and 100 as the maximum.
• Check whether your teacher rounds percentages before grading — this calculator does not round up.
• For a university with fixed credit-based rules, use a calculator built for those rules instead, such as the VIT CGPA Calculator. For a plain marks-to-percentage sum, use the Percentage Calculator for Marks.

Limitations

This calculator does the arithmetic exactly for the scores, weights and scale entered, nothing more. It does not know about a teacher’s dropped-lowest-score policy, late penalties, curved grading, or a school’s own rounding convention — all of those change the final grade and none of them can be read from the raw scores alone. Treat the result as a working estimate and confirm it against the course’s own grading policy before relying on it.

Frequently asked questions