Math Calculators
Grade Calculator
A weighted course grade is the mean of your scores where each one counts by its own weight: every score is multiplied by its item's weight and the total is divided by the weight entered. This calculator also names the letter band the grade lands in and the score your final exam needs to reach a target.
Calculator
Formula
Weighted grade = Σ(weight × score) ÷ Σweight. Score needed on the final = (target × (weight counted + final weight) − current grade × weight counted) ÷ final weight.
About This Calculator
What It Does
This calculator turns a list of graded items into a course grade. Give each item a weight — its share of the final grade — and the score you earned on it, and the calculator returns the weighted grade, the letter band it lands in, and, if you enter a target and the final exam's weight, the score the final must reach.
Worked Example
The page opens with three items worth 20 %, 20 % and 30 % and scored 90, 70 and 80. Their weights add to 70 %, and the final exam is worth the remaining 30 %. Weighted grade = (20 × 90 + 20 × 70 + 30 × 80) ÷ 70 = 5600 ÷ 70 = 80.00. Letter band: 80 falls in B- (80–82). With a target of 85 %, the final must score (85 × 100 − 80 × 70) ÷ 30 = 2900 ÷ 30 = 96.67 %. So an 80.00 is banked, and a 96.67 on the final would lift the course to 85.
Real-World Usage
Use it to work out where a course stands before the last assignment, to check whether a target grade is still reachable, to see how much a heavy final counts, or to compare what a grade does under different weights.
Local Context
Grading rules, weights and letter bands are set by each school, so this is an estimate. The letter bands used here are the common US scale (90–92 % is an A-, below 60 % an F); a school that reports only percentages can read the percentage, and one on another scale can treat the letter as a guide. The target-final formula is the standard one and does not model penalties, rounding rules or extra credit.
Last reviewed: October 2026.
Frequently Asked Questions
How do I calculate my course grade?
Multiply each item's score by its weight, add those products up and divide by the total weight. With items weighted 20 %, 20 % and 30 % and scored 90, 70 and 80, the grade is (20 × 90 + 20 × 70 + 30 × 80) ÷ 70 = 5600 ÷ 70 = 80 %. The calculator normalises over the weight you entered, so the weights do not have to add up to 100.
Do my weights have to add up to 100?
No. The weighted grade is divided by the weight you entered, not by 100, so a set that adds to 70 % is averaged over 70 %. That is what makes the figure the grade so far, with the remaining weight still to come.
How do I work out what I need on the final?
Enter your target grade and the final exam's weight. The calculator solves (target × (weight counted + final weight) − current grade × weight counted) ÷ final weight. A result above 100 % means the target cannot be reached at that final weight, and a result below 0 % means you have already secured it.
What does the letter band mean?
The letter is the standard US band your percentage falls in: 90 to 92 % is an A-, 83 to 86 % is a B, 73 to 76 % is a C, and below 60 % is an F. Schools set their own bands, so treat the letter as a guide and your institution's scale as the authority.