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Grade calculator

A grade calculator finds a weighted course average as G = Σ(scoreᵢ × weightᵢ) ÷ Σweightᵢ. Homework at 95% worth 20%, a midterm at 88% worth 30%, and a final at 92% worth 50% produce an overall grade of 91.4%, which is an A− on the standard US letter scale and 3.7 grade points on the 4.0 scale.

Score is a percentage. Weight can be a percentage or any relative number — only the ratio matters.

%
Calculated in your browser — nothing is uploaded.

Result

Overall weighted grade — A−

91.40%

G = Σ(scoreᵢ × weightᵢ) ÷ Σweightᵢ

Letter grade
A−
Grade points (4.0 scale)
3.70
Total weight entered
100
Homework (weight 20)
95.0%
Midterm (weight 30)
88.0%
Final exam (weight 50)
92.0%

Across 3 assessments totalling 100 weight units, the weighted average grade is 91.40%, which is a A− on the standard US letter scale and 3.7 grade points on the 4.0 scale.

How to use the grade calculator

  1. 01

    List your assessments

    Enter one assessment per line in the form “name, score, weight”. Score is a percentage; weight can be a percentage or any relative number.

  2. 02

    Add every graded item

    Include homework, quizzes, labs, papers and exams. Any item left out shifts the average toward the items that remain.

  3. 03

    Set a target grade

    If the entered weights total less than 100, type the overall grade you are aiming for to see the score required on what is left.

  4. 04

    Read the result

    The result strip shows the weighted average and its letter grade. The rows beneath list each assessment and the 4.0-scale grade points.

The formula

G = Σ(scoreᵢ × weightᵢ) ÷ Σweightᵢ        needed = (target − G × (1 − w)) ÷ w
G
The overall weighted grade as a percentage.
scoreᵢ
The percentage earned on assessment i.
weightᵢ
The relative weight of assessment i. Only the ratio matters, so weights need not sum to 100.
target
The overall grade you are aiming for.
w
The share of the final grade still outstanding, as a decimal.
needed
The score required on the remaining work to reach the target.

Weights are relative, not absolute. Entering 20, 30 and 50 gives the same answer as entering 2, 3 and 5. When the entered weights total less than 100, the calculator treats the remainder as outstanding and computes the score needed on it.

Worked example

Assessments
Homework 95% (weight 20) Midterm 88% (weight 30) Final exam 92% (weight 50)
Target grade
90%
Result
91.40% — A−

Multiply each score by its weight: 95 × 20 = 1,900, 88 × 30 = 2,640, and 92 × 50 = 4,600. Sum the products: 1,900 + 2,640 + 4,600 = 9,140. Sum the weights: 20 + 30 + 50 = 100. Divide: 9,140 ÷ 100 = 91.40%. On the standard US scale that is an A−, worth 3.7 grade points. The target of 90% is already exceeded, so no further score is required.

Frequently asked questions

How do you calculate a weighted grade?

Multiply each score by its weight, add the products together, then divide by the sum of the weights. For scores of 95, 88 and 92 with weights of 20, 30 and 50, the products total 9,140 and the weights total 100, giving 91.40%. Averaging the three scores without weighting would give 91.67% — a different and incorrect answer.

What score do I need on the final exam?

Use needed = (target − current × (1 − w)) ÷ w, where w is the final exam's share of the grade as a decimal. Holding 85% across 70% of the course and targeting 90% overall requires (90 − 85 × 0.7) ÷ 0.3 = 101.67% on the final — mathematically out of reach without extra credit.

What percentage is an A grade?

On the most common US scale, an A is 93 to 96%, an A+ is 97% and above, and an A− is 90 to 92%. B grades run from 80 to 89%, C from 70 to 79%, D from 60 to 69%, and F below 60%. Institutions vary, so the registrar's published scale governs any official transcript.

Do weights have to add up to 100?

No. Only the ratio between weights affects the result, so 2, 3 and 5 produce exactly the same average as 20, 30 and 50. Weights totalling less than 100 are useful mid-semester: the calculator treats the shortfall as outstanding and computes the score needed on it to reach a target.

How does dropping the lowest grade change the average?

Remove that assessment's line entirely and recalculate. Both the numerator and the denominator shrink, so the effect is larger than it first appears — dropping a 40% from a set of 90s can lift an average by several points. Where a syllabus replaces a dropped score rather than removing it, enter the replacement instead.

What is the difference between a weighted and an unweighted grade?

An unweighted average treats every assessment as equally important, which is only correct when every assessment carries the same weight. A weighted average scales each score by its stated share of the final grade. Since a final exam typically counts for far more than a single homework set, weighting is what makes the number meaningful.

Sources

Last reviewed: · Formula and sources verified by Syed Aqeel Ahmad Gillani. See the methodology for how every calculation is derived.

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