Weighted Average Calculator - Weighted Mean, Grades & Target Score
Weighted Average Calculator
Average values that count for different amounts, and find the score you need next
Any Weights
Weights can be percentages, credits, hours or any positive numbers; they do not have to add up to 100.
Target Score
Set a target average and the weight of what is left, such as a final exam, to see the score you need.
See What Counts
Each row shows its share of the total weight and how many points it contributes to the result.
Full Privacy
Everything is calculated in your browser.
What Is a Weighted Average?
An ordinary average treats every value equally. A weighted average lets some values count more: multiply each value by its weight, add the results, and divide by the total weight. If homework (90) is worth 30%, quizzes (80) 20% and the exam (70) 50%, the result is (90×30 + 80×20 + 70×50) ÷ 100 = 78, lower than the simple average of 80 because the lowest score carries the most weight.
Weighted averages appear in grades and GPAs, portfolio returns, index prices, and survey results. To find the score you need on the last item, the calculator solves the same equation backwards: needed = (target × total weight − points so far) ÷ weight of the next item.
Key Takeaways
- Flexible: Add or remove as many rows as you need.
- Comparison: Shows the simple average next to the weighted one.
- Validated: Negative weights and all-zero weights are rejected with a clear message.