Grade Calculator

How a weighted grade is calculated

Most syllabi split the course grade into categories, each with a weight. To get the grade:

1. Multiply each category’s score by its weight: 90 × 20 = 1,800; 85 × 20 = 1,700; 78 × 25 = 1,950.
2. Add the results: 5,450.
3. Divide by the total of the weights used: 5,450 ÷ 65 = 83.85%.

The weights here add up to 65% because the final exam has not been graded yet, so 83.85% is the grade so far — a B on the scale below. Once every category has a score and the weights add up to 100%, the same calculation gives the final course grade.

If a category has several scores — ten homework assignments, say — average them first, the way your teacher does: add up points if the assignments are out of different totals, or average the percentages if each one counts the same. Then enter the category once with its weight. Dropped lowest scores and extra credit change that category average, not the formula.

What you need on the final

Leave the grade of the final exam empty and enter its weight. The calculator works out the score the final needs for each letter:

needed = (goal × all weights − grade so far × weights graded) ÷ weight of the final

With 83.85% on 65% of the course and a 35% final, a B (83%) needs (83 × 100 − 83.85 × 65) ÷ 35 = 81.43%. A C needs 52.86%, and an A would need 110%, which is not possible without extra credit. Type your own target in Goal — a percentage or a letter — to see the score for it. The same formula works for any work still to come, such as the last project and the final together: enter both with their weights and no grade.

Weights that do not add up to 100

The calculator divides by the weights you entered, so weights of 15, 25 and 30 give the average of those three categories on a 70% base. That is the right answer during the term, and it is what school grade portals show. If your weights add up to more than 100 — an extra-credit category, for example — the result is still a weighted average; check the syllabus for how bonus points are capped.

Points or percentages

Classes graded on total points do not use weights at all: every point counts the same. Enter scores as fractions — 45/50, 18/20, 72/80 — and leave the weights empty. The calculator adds the points: 135 out of 150 is 90%. Averaging the three percentages instead would give 90.0% here only because the tests are similar in size; with 9/10 and 70/100 the point total is 71.8%, while the average of 90% and 70% is 80%. For quick percent conversions of a single score, use the percentage calculator; to add or compare fractions of points, the fraction calculator.

Letter grades and the 4.0 scale

This plus-and-minus scale is common in U.S. high schools and colleges, but it is not universal. Some schools use a 10-point scale without pluses and minuses — A from 90, B from 80, C from 70 — and the College Board notes that schools set their own cutoffs. Some give an A+ 4.3 points. The cutoffs here do not round, so 86.9% is a B; teachers who round to the nearest whole percent would make it a B+ at 86.5% or higher.

Averaging letter grades

When every grade is a letter, the calculator converts each to grade points, weights them, and reads the average back as the nearest letter: A (30%), B+ (30%) and C (40%) give (4.0 × 30 + 3.3 × 30 + 2.0 × 40) ÷ 100 = 2.99, a B. If letters are mixed with percentages, each letter counts as the middle of its range — a B as 84.5% — and the result says so. For several courses with credit hours, that is a GPA, which weights each course by its credits instead of by a syllabus percentage. For long or unusual weight sums, the scientific calculator helps check the arithmetic.