**Instructions**: Use this tool to calculate your grade. If you know all your scores, you can calculate your final score and final letter grade. If you don't all of your scores you can find out what score you need to get in order to get an A in the class.

**Step 1:**You have space for up to 10 assignment/test scores. Please type the scores on the left, and the percentage of total grade for each assignment (without the % sign). Please leave empty the unused cells. If you know all the scores (so then the percentages will add up exactly to 100%), the calculator will tell your final score and your final letter grade.

**Step 2:**If you still don't have all your scores (so the total percentage of scores provide is still less than 100%), the calculator will tell you what score you need to get an A in the class.

**Step 3:**Finally, you need to type the letter grades used in your class, and the minimum score to get each letter grade. Initially the table suggests a common arrangement of letter grades, but you can modify the values to fit your class. After that you can click on "Calculate Grade"

**More about this grade calculator**, so you understand how it computes the grade (if you already understand the math behind, you can skip this part).

The main principle behind the calculation of a final score is the concept of *weighted average*. Say you have (n) scores which we call
(x_i) and each score has an associated weight (w_i). The final score is computed by calculating the weighted average (sum_{i=1}^{n} x_i cdot w_i)

Once you have your final score, a final **letter grade** will be assigned depending on the ranges specified by your teacher. Some teachers use some very arbitrary methods to decide which scores are an A, which are B, etc.

Others define the ranges by certain percentiles of the class (ex: the top 10% will get A only), others use statistical distributions to do so, etc.

In case you have any suggestion, please do not hesitate to contact us.