What grade do I need to get on the final to get a C in the course?
Calculating your course grade using the grade point method

There are many different ways to figure course grades. The method described here is the simple grade point method in which the final grade is calculated as the weighted average of the numerical equivalents of the letter grades for each course component. By using this method you can get a good idea of what your grade is and what effect a particular grade on an upcoming test will have on your overall course grade. Due to special circumstances, the actual grade determination process may differ from the one described here.

Since writing this description, I have added a spreadsheets to the class web site that will do these caluculation automatically for a course with similar grading system. Follow the links here to go to spreadsheets used for a recent statistics class and a recent labor economics class.

As a first step, you should set up a table to organize your calculations. This can be done by hand or by using a computer spreadsheet program. Of course the spreadsheet program will make recalculating the course grade easier. The table should look something like the one shown here. The number of components and the weights assigned to them may be different for your class. Be sure to check your course outline to be sure you have these table entries correct.

Component	Grade	Grade points	Component weight	Grade points x component weight
Homework and Quizzes			0.10
Test 1			0.20
Test 2			0.20
Test 3			0.20
Test 4			0.30
Total			1.00

Next fill in the letter grades that you have received so far. You can also fill in grades for tests that you have not taken yet if you want to see what effect these hypothetical grades you have entered for those tests will have on your overall grade. Suppose, for example, that you are getting a B+ on your quizzes, and that you received a B- and an A- on your first two tests respectively. In this case, your table would look like the following:

Component	Grade	Grade points	Component weight	Grade points x component weight
Homework and Quizzes	B+		0.10
Test 1	B-		0.20
Test 2	A-		0.20
Test 3			0.20
Test 4			0.30
Total			1.00

Now you need to fill in the numerical equivalents of the letter grades using the standard scale where an 4.0 is equivalent to an A and 3.0 is equivalent to a B, etc. Letter grades can be converted to their numerical equivalents using the following table:

Using the hypothetical example here, the grade calculation table should now look like this:

Component	Grade	Grade points	Component weight	Grade points x component weight
Homework and Quizzes	B+	3.33	0.10
Test 1	B-	2.67	0.20
Test 2	A-	3.67	0.20
Test 3			0.20
Test 4			0.30
Total			1.00

Next multiply the grade points by the associated component weight and put the result in the far right column. Using the example here the table looks like this:

Component	Grade	Grade points	Component weight	Grade points x component weight
Homework and Quizzes	B+	3.33	0.10	0.33
Test 1	B-	2.67	0.20	0.534
Test 2	A-	3.67	0.20	0.734
Test 3			0.20
Test 4			0.30
Total			1.00

Next you need to find the sum of the values in the far right column. Enter this value in the bottom cell in the far right column. Using this example, the table should look like the following.

Component	Grade	Grade points	Component weight	Grade points x component weight
Homework and Quizzes	B+	3.33	0.10	0.33
Test 1	B-	2.67	0.20	0.534
Test 2	A-	3.67	0.20	0.734
Test 3			0.20
Test 4			0.30
Total			1.00	1.601

Now find the sum of the component weights for the course components on which you are basing your calculations. In this case the sum of the component weights used is 0.10 + 0.20 + 0.20 = 0.50. This implies that you have completed 50% of the course. Note that in this example, a little less than 50% of the course has been completed if there are still some quizzes to be taken.

The next step is to divide the total in the far right column by the total of the component weights used. Here we would divide 1.601 by 0.50 to get 3.202. This result represents your weighted average grade points in the course so far.

Finally, you need to convert this number back to a letter grade. The following table shows the minimum weighted average grade points necessary to get the associated grade. This scale is different - a little lower - than the one above for a number of reasons. The primary reason is can be illustrated this way: If the scale above were used then a student who received an A on every test but just an A- on the quizzes then the weighted grade point average would be something less than 4.0. Unless the scale were adjusted downward as shown here, the student would receive an A- even though 90% of the course work was A level. With the example given here, the current grade points of 3.202 work out to a B+.

At this point you can use a trial and error method to see what effect hypothetical grades on the next course components will have on your overall grade. For example, we can see that if the student in this example gets an A on Test 3 and an A- on the final, the calculation table will look like the following:

The weighted average grade points are equal to 3.502 divided by the total of all the component weights which is 1.00. Thus the weight average grade points are 3.502 / 1.00 = 3.502. With these grades, the student will get an A- for the course.