Weighted Average Calculator
Weighted mean of scores, grades or prices, and the score you need to hit a target.
About this tool
Add each item with its value and its weight. A weight can be a percentage of the course, credit hours, a quantity or anything else that measures importance. The weighted average, each item's share and the plain average all update as you type. Enter the weight still to come and a target to see the score you need.
How a weighted average works
A plain average treats every number equally. A weighted average lets some count more than others: multiply each value by its weight, add those up, and divide by the total weight. Weights don't need to add up to 100. Homework worth 20% with a score of 88 and a midterm worth 40% with a score of 74 give (88 ร 20 + 74 ร 40) รท 60 = 78.67 so far. If the final exam is worth the remaining 40% and you want 80 overall, you need (80 ร 100 โ 4,720) รท 40 = 82 on it. The same formula gives a GPA weighted by credit hours, the average price per share across several purchases, a portfolio's average return weighted by amount invested, or the average speed over legs of different lengths. If the required score is above 100, the target can't be reached on a 100-point scale. If it's negative, you've already secured it. Honest limits: the answer is only as good as the weights. Check your syllabus, because some courses drop the lowest score, cap marks or curve the result. The grade calculator, the GPA calculator and the average calculator are related, and What do I need on the final? explains final-exam targets.
Frequently asked questions
How do you calculate a weighted average?
Multiply each value by its weight, add the results, and divide by the sum of the weights.
Do the weights have to add up to 100?
No. Any positive weights work, because the formula divides by their total.
How do I find what I need on my final exam?
Enter your scores so far with their weights, then the final's weight and your target. The tool solves for the score needed.
Is anything saved?
No. Calculations happen in your browser and nothing is stored or sent.