Grade Calculator
The grade calculator can help you estimate your overall grade based on your component marks. The tool deals with three types of grading systems prevalent in the US  it's a letter grade calculator, a grade percentage calculator, and a point grade calculator.
In the text, you can learn how to use the grading calculator and how to determine an overall grade without it. Find out how to calculate weighted grades, how to calculate grade percentage, and more.
You can use the tool as an unweighted or weighted grade calculator, and set the particular grading scale your teachers use.
How this grading calculator works?
We divided the tool into three parts  a letter grade calculator, a grade percentage calculator, and a point grade calculator. You can enter up to 20 marks (new fields will appear once you fill in the last row displayed).
The weights are by default set to 1. Leave them as they are if you want to calculate unweighted average. If your grades have weights, set them accordingly. If the weights are percentages, enter them in decimal form (1 = 100%, 0.5 = 50%, 0.2 = 20%
, etc.).
Schools and universities in the United States use different grading scales. You can specify the thresholds used by your teachers in the advanced mode
(click the button below the grading calculator). By default, the calculator uses this common grading scale:
Letter Grade  Percentage  GPA (Grade Point Average) 

A+  97100  4.3 
A  9396  4.04.29 
A  9092  3.73.99 
B+  8789  3.33.69 
B  8386  3.03.29 
B  8082  2.72.99 
C+  7779  2.32.69 
C  7376  2.02.29 
C  7072  1.71.99 
D+  6769  1.31.69 
D  6366  1.01.29 
D  6062  0.70.99 
F  Below 60  0.00.69 
Some schools don't use "+/". In this case, the most popular grading scale looks like this:
Letter Grade  Percentage  GPA 

A  90100  3.7–4.0 
B  80–89  2.7–3.69 
C  70–79  1.7–2.69 
D  60–69  0.7–1.69 
E / F  059  0.0–0.69 
Letter grade calculator
The letter grading system is common in the US. Let's see how to use the letter grade calculator:

If your school uses a different grading scale than the one described in the first paragraph, go to the
advanced mode
and set the grading scale. 
Set the
Grades type
to "Letters." 
In the first field, choose the grade you got from the first assignment, test, exam, or subject.

If your grades have weights or credits, enter the weight of the first grade. You can enter a natural number, a decimal, or change the unit to a percentage. If the weight is a percentage, you can input its decimal form (e.g., 0.5 for 50%).
If you're calculating the unweighted average (all grades are equally important), ignore the letter grade calculator's
weight
fields. 
Proceed this way with all your marks. New rows will appear as you fill in the last field.

Your overall grade will appear at the bottom of the letter grade calculator.
If you want to clear all the fields and make the calculator grade again, click the circular arrow icon to reload it.
Grade percentage calculator
To use the grade percentage calculator:

Set the
Grades type
to "Percentage." 
Type in the percentage result of your first test, task, or subject. Underneath, enter the weight or credits given for the grade. Ignore this field if your teacher doesn't use weights.

Continue to enter the percentage grades of all your assignments, tests, etc., along with their weights. New rows will appear once you fill the last field.

The grade percentage calculator will display the average of your marks. It'll also tell you the equivalent letter grade. The calculator is based on the default grading scale, so change it in the
advanced mode
if you need to.
Grade calculator points
To use the point grade calculator:

Set the
Grades type
to "Points." 
Enter how many points you got from the first task, assignment, or subject. Then type in the maximum number of points you could get for the task.

Set the weights (credits) if applicable.

Enter the rest point grades, along with both maximum points and weights.

The point grade calculator will show you how many points you achieved in total, and what was the maximum you could have got (your score/max, while ignoring the weights). You'll also see the equivalent percentage and letter.
How to calculate weighted grades?
The formula that lets you calculate weighted grades is:
(g₁*w₁ + g₂*w₂ + ... + gₙ*wₙ) / (w₁ + w₂ + ... + wₙ)
,
where:
 "g" stands for "grade"; and
 "w" stands for "weight".
This is what the weighted grade calculator uses.
The formula answers the question "how to calculate weighted grades." We could translate it into some instructions:
 Multiply all your grades by their weights.
 Sum the numbers from step 1.
 Sum the weights.
 Divide the sum from step 2 by the sum from step 3.
Weights tell you how important the grade is. Imagine you got a grade B with a weight 2 and an A with a weight 5. It's as if you got two Bs and five As. Let's find the overall grade from these marks.
First we need to convert letters to numbers. "A" stands for 4 and "B" equals 3. Now that we know this, let's use the formula described above and calculate the weighted average of all grades:
(3 * 2 + 4 * 5) / (2 + 5) = 26 / 7 ≈ 3.71
We translate the result back to a letter: 3.71 is an "A."
How to calculate the grade percentage?
In the case of percentage grades, we use the same formula as for letter grades.
Example: you're finishing a year and want to calculate your overall grade for a class. You got 67% for an essay worth 15% of the grade, 75% for a midterm exam worth 35%, and 72% for a final worth 50%.
Let's apply the formula. Remember to convert the weights from percentage to a decimal. The weights add up to 1 (100%), so you can skip the denominator part of the formula.
67% * 0.15 + 75% * 0.35 + 72% * 0.5 = 10.05% + 26.25% + 36% = 72.3% ≈ 72%
Your final grade is 72%, which can be denoted as C.
How to calculate my grade points?
In the case of point grades, we can convert them to percentages and assign a letter equivalent if needed. We can use the following formula for point grades:
p₁/p_{1,max} * w₁ + p₂/p_{2,max} * w₂ + ... + pₙ/p_{n,max} * wₙ) / (w₁ + w₂ + ... + wₙ)
,
where
p
 points acquired on a test;p_{max}
 maximum number of points on a test; andw
 weight of a grade.
Example: I got 70/100 points on the first test, 46/100 on the second one, and 177/200 on the third one. The first test constitutes 30% of my overall grade, and so does the second one. The third one is worth 40%. Calculate my grade.

Let's substitute our values into the formula:
grade = (70/100 * 30% + 46/100 * 30% + 177/200 * 40%) / (30% + 30% + 40%)
Usually, when we express weights in percentages, they add up to 100% (or just one in decimal notation). In these cases, you can skip the denominator part of the formula (since dividing by one doesn't change the result).

We convert the percentages to decimals:
grade = (70/100 * 0.3 + 46/100 * 0.3 + 177/200 * 0.4) / (0.3 + 0.3 + 0.4)
. 
We convert the points (grades) to percentages and the weights add up to 1:
grade = (70% * 0.3 + 46% * 0.3 + 88.5% * 0.4) / 1
. 
We add up the numbers and round the result:
grade = 21% + 13.8% + 35.4% = 70.2% ≈ 70%
. 
We assign a letter:
70% is a C
.