Weighted Average Calculator
This weighted average calculator finds the mean when some values count more than others. Add a row for each value and the weight it carries, and you'll get the weighted average along with the total weight and a plain average to compare. The weights don't have to add up to 100, so use percentages, credit hours, or counts. It's free, private, and updates as you type.
- Weighted mean
- Any number of rows
- Any weight scale
- Total weight
- Simple average too
Last updated June 17, 2026 Weights need not sum to 100 Reviewed by the Calcowa team
Each row is a value and how much it counts. Leave a weight blank or zero to skip that value.
8,400 ÷ 100 = 84
How do I calculate a weighted average?
A weighted average is a mean where each value carries its own importance, called a weight. You multiply every value by its weight, add those products, and divide by the sum of the weights. So a 90 worth 40 and an 80 worth 60 give 3,600 plus 4,800, which is 8,400, over a total weight of 100, landing at 84. A plain average of the same two numbers is 85, so the heavier 80 pulls the weighted result down. This weighted average calculator handles any number of rows and any weight scale, since dividing by the total weight normalizes it, and it shows the simple average beside the weighted one so you'll see the gap. You won't need to track the products, and it's the same math whether you're blending grades or returns.
A two-value example, step by step
Here's a 90 weighted 40 and an 80 weighted 60. It's the same method the tool runs for any number of values, and you'll see it match the boxes above:
- 1
Multiply each pair90 times 40 is 3,600, and 80 times 60 is 4,800.
- 2
Add the products3,600 plus 4,800 is 8,400 in total.
- 3
Add the weightsThe weights 40 and 60 sum to 100.
- 4
Divide for the average8,400 divided by 100 is a weighted average of 84.
Where weighted averages show up
Here are common places a weighted average beats a plain one, with what plays the role of the weight. They're everyday cases, and the calculator works the same in each, so you don't need a different tool for grades versus money.
| Use | Value | Weight |
|---|---|---|
| Course grade | Score | Percent of grade |
| GPA | Grade points | Credit hours |
| Portfolio return | Return | Amount held |
| Survey result | Group score | Group size |
| Decision score | Rating | Factor importance |
Frequently asked questions
Multiply each value by its weight, add those products, then divide by the total of the weights. So a 90 worth 40 and an 80 worth 60 give (3,600 + 4,800) over 100, which is 84. This weighted average calculator does it for every row you add, so you don't track the products and weights by hand, and it updates the moment you type.
A simple average treats every value equally, while a weighted average lets some count more than others. The same 90 and 80 average to 85 the simple way, but if the 80 carries more weight, the weighted result drops below that. The tool shows both, so you'll see how much the weighting moves the result.
Anything where parts matter unequally: course grades where the final counts more than a quiz, a portfolio where each holding is a different size, survey scores with different sample sizes, or a decision matrix where some factors outrank others. The weights just say how much each value pulls on the result, and they don't have to add up to 100.
No. The formula divides by the total of the weights, so any scale works, whether they sum to 100, to 1, or to something else. You can use percentages like 40 and 60, credit hours like 3 and 4, or plain counts. The calculator normalizes them for you, so you'll get the right answer no matter the scale.
A value with a zero weight is ignored, since it contributes nothing to the total. That's handy for dropping an item without deleting the row. If every weight is zero, there's nothing to divide by, so the tool falls back to a simple average of the values instead, which keeps a sensible result on screen.
Yes to both. There's no sign-up, no limit, and nothing to install, since it runs in your browser. The numbers you type stay on your device and aren't sent anywhere. Bookmark it for grades, investing, or any time some values should count more than others, and it'll be a tap away.
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Some values count more?
Weight them above, or browse all education tools.