How is a weighted grade calculated?

Each category's score is multiplied by its weight, the products are summed, and the total is divided by the sum of the weights. This gives a weighted average where heavier categories like tests influence the final grade more than lighter ones.

Do the weights have to add up to 100?

Not necessarily. The tool divides by the actual sum of weights, so 40, 30, 20, and 10 work the same as any set that totals 100. If your weights sum to something else, the result is still correct because it normalizes by the total.

What if a category has no score yet?

Leave that category's score blank and it is excluded from both the weighted total and the weight sum, so the grade reflects only completed work. This lets you see a running grade before every category is filled in.

How is the letter grade decided?

The weighted percentage is mapped on a standard scale: A is 90 and up, B is 80 to 89, C is 70 to 79, D is 60 to 69, and F is below 60. The exact percentage is always shown alongside the letter.

Is any student data saved?

No. All calculations run locally in your browser and nothing is uploaded or stored after you close the page, so student grades remain private to your device.

Teacher Grade Book Calculator

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The Teacher Grade Book Calculator computes a final grade from category weights, the way most modern grade books work. Instead of averaging every assignment equally, categories like homework, quizzes, tests, and projects each carry a weight, and a student’s category averages combine into one weighted final. This tool does that math instantly and assigns a letter grade.

How it works

Each category supplies a percentage score and a weight. The calculator computes the weighted average as final = Σ(score × weight) / Σ(weight). Because it divides by the actual sum of weights, your weights do not have to total exactly 100 — they are normalized automatically. A category left blank is excluded from both sums, so you can see a running grade before all work is entered. The resulting percentage maps to a letter on a standard scale (A ≥ 90, B ≥ 80, C ≥ 70, D ≥ 60, else F).

Example and tips

Suppose the weights are Homework 10%, Quizzes 20%, Tests 50%, Projects 20%, and a student scores Homework 95, Quizzes 88, Tests 82, Projects 90. The weighted total is (95×10 + 88×20 + 82×50 + 90×20) / 100 = 86.1, a B. Tips: keep your category weights consistent across the class for fairness, leave future categories blank to watch a live running grade, and remember that because tests carry the most weight here, they move the final grade the most.