Weighted Average Calculator: For Grades, Stats, and More
A weighted average is not the same as a regular average. In a regular average, every value counts the same, add them up, divide by the count, and done. In a weighted average, some values matter more than others. If you are calculating your grade and the final exam counts twice as much as a quiz, that is a weighted average. If you’re calculating the mean of a dataset where some data points are more reliable than others, that is also a weighted average.
This calculator handles weighted averages for grades, statistics, finance, or any scenario where different values have different levels of importance. Enter your values, assign weights to each, and it calculates both the weighted and simple averages so you can see the difference.
What Is a Weighted Average?
A weighted average is a type of mean where each value has a weight that determines how much it contributes to the final average.
Here is the simplest possible example. You have three test scores: 80, 90, and 100. A regular (simple) average treats them all equally: (80 + 90 + 100) ÷ 3 = 90%.
Now add weights. Say the first test counts for 1 point, the second counts for 2 points, and the third counts for 3 points. The weighted average is: (80×1 + 90×2 + 100×3) ÷ (1+2+3) = (80 + 180 + 300) ÷ 6 = 560 ÷ 6 = 93.33%.
The third test (100%) had the highest weight, so it raised the average relative to the simple average.
The formula is straightforward:
Weighted Average = Σ(value × weight) ÷ Σ(weights)
That is it. Multiply each value by its weight, add up all the products, then divide by the sum of the weights.
Weighted averages exist because not all data are created equal. In academic grading, a final exam is usually more important than a homework assignment, so it gets a higher weight. In statistics, when averaging measurements, you might weight the more precise ones more heavily. In finance, if you are calculating the average return on a portfolio, stocks you own more of should count more in the average.
This calculator does the multiplication and division for you. You enter the values and the weights, and it outputs both the weighted and simple averages side by side for comparison.
How to Use This Calculator
The calculator uses rows. Each row is one value with its weight. The default setup has four rows (Assignment, Quiz, Midterm, Final exam), but you can add or remove rows to match your calculations.
Each row has five inputs:
1. Item/name: This is optional. It is just a label to keep track of what each row represents. You can leave it blank if you want.
2. Type: This dropdown has three options: Points, Percent (%), or Letter (A–F). Pick whichever format your value is in.
- Points: You enter the value and the total possible (e.g., 85 out of 100).
- Percent: You enter the percentage directly (e.g., 88%).
- Letter: You pick a letter grade from the dropdown (e.g., B+). The calculator converts it to a percentage based on the current grading scheme.
3. Value / % / Letter: This input changes based on the type you selected. If you picked Points, you enter the earned score. If you picked percent, you enter the percentage. If you picked Letter, a dropdown appears with all the letter grades from the current scheme.
4. Out of (points): This only shows up if you selected Points as the type. Enter the total possible points here.
5. Weight: This is how much this row counts relative to the others. The weights do not have to sum to a specific value; they only need to represent relative importance. If one row has a weight of 30 and another has a weight of 10, the first row counts three times as much.
Once you have filled in your rows, hit Calculate. The result card on the right shows your weighted average, letter grade, GPA, total weight, simple average, and the range (lowest to highest value).
The Simple Average Comparison: Why It Matters
One of the outputs on the result card is “Simple avg”, which is the unweighted average of all your values. It is displayed right next to the weighted average so that you can see the effect of weighting.
Here is why this comparison is useful. When you are calculating a weighted average, the math can be abstract. You enter values and weights, and the calculator gives you a number, but it is not always obvious how much the weighting actually mattered. The simple average gives you a baseline.
For example, say you enter four test scores with weights: 85% (weight 10), 90% (weight 20), 78% (weight 10), 92% (weight 30). The calculator shows:
- Weighted average: 88.71%
- Simple average: 86.25%
The difference between those two numbers, about 2.5 percentage points, is the effect of the weighting. The higher-weighted tests (90% and 92%) raised the weighted average relative to the simple average.
In academic grading, this tells you how much your course’s weighting structure is helping or hurting you. If your weighted average is higher than your simple average, the weighting is working in your favor; your better scores are weighted more heavily. If it is lower, your weaker scores are weighted more heavily and drag the average down.
In other contexts, such as statistics and finance, the comparison between weighted and unweighted averages can show you whether your weighting scheme is meaningfully changing the result or just adding complexity for no real benefit.
Mixing Types: Points, Percents, and Letters in One Calculation
This calculator has a feature that most weighted average calculators don’t: you can mix different input types in the same calculation.
Here is a scenario where that matters. You are calculating your grade in a course. You have:
- Homework average: 85 out of 100 (points)
- Quiz average: 88% (percent) Midterm: B+ (letter grade)
- Final exam: 180 out of 200 (points)
On most calculators, you would have to convert everything to the same format first, either all points or all percentages. That is extra work and introduces rounding errors if you are not careful.
On this calculator, you enter each row in its natural format. Set the homework row to Points and enter 85 / 100. Set the quiz row to percent and enter 88. Set the midterm row to Letter and pick B+ from the dropdown. Set the final row to Points and enter 180 / 200.
Behind the scenes, the calculator converts all inputs to percentages under the current grading scheme, then computes the weighted average. You do not have to touch the conversions yourself.
This flexibility is especially useful when you’re working from multiple sources. Your syllabus might list some things as percentages, some as points, and some as letter grades. You can enter them exactly as they appear without reformatting the entire text first.
The only requirement is that you pick a grading scheme at the top that applies to the whole calculation. The letter-to-percentage conversions use that scheme’s thresholds.
Weighted Average for Grades vs. Stats vs. Finance
“Weighted average” is a general math concept, and it shows up in three main contexts. This calculator works for all three, but it is worth understanding which one applies to your situation.
Grades / Academic: You are calculating a course grade based on categories like homework, quizzes, exams, and projects. Each category has a weight, typically as a percentage that sums to 100%. Your final grade is the weighted average of your scores in each category. This is probably the most common use case for this calculator. The result card includes a letter grade and GPA because those are meaningful in an academic context.
Statistics / Research: You are calculating the mean of a dataset where some data points are more reliable, more recent, or more important than others. For example, you might average survey responses and weight them by sample size, or average measurements and weight them by precision. In this context, the letter grade and GPA outputs don’t mean anything; you would use the weighted average percentage as your result. The calculator still works; you ignore the academic outputs.
Finance / Investing: You are calculating a weighted average return on a portfolio, where each stock’s weight is determined by how much of the portfolio it represents. Or you are calculating a weighted average cost of capital. The math is identical to the other two contexts; it is still Σ(value × weight) ÷ Σ(weights). Again, ignore the letter grade and GPA; they’re not relevant to finance.
This calculator does not have separate modes for these three contexts because the underlying math is the same. The only difference is what the inputs represent and which outputs you care about. If you are here for grades, you care about the letter grade and GPA. If you’re here for stats or finance, you only care about the weighted average percentage.
If you are specifically looking for a calculator built around academic grading categories and syllabi, the weighted grade calculator is designed exactly for that. It includes features such as drop-lowest and normalize weights, which are specific to grading. This calculator is more general-purpose.
When Weights Do not Add to 100
A common question: do the weights need to add up to 100? Or to any specific number?
No. The weights are relative, not absolute. What matters is the ratio between them.
If you enter weights of 10, 20, and 30, that’s the same as entering 1, 2, and 3. Or 100, 200, and 300. Or 16.67, 33.33, and 50. All of those produce the same weighted average because the ratios are the same: the second weight is twice the first, and the third is three times the first.
In academic grading, weights are usually listed as percentages that add to 100: “Homework 20%, Quizzes 30%, Final 50%.” That is a convention, not a mathematical requirement. You could enter those as 2, 3, and 5 and get the same result.
The calculator shows “Total weight” in the result card, which is just the sum of all the weights you entered. It is mostly there for reference. If you’re working from a syllabus that says the weights should add to 100 and your total is 95, you know you missed something. But mathematically, it doesn’t affect the weighted average calculation.
This Calculator vs. the Weighted Grade Calculator
There are two weighted calculators on this site: this one and the weighted grade calculator. They are related but serve different purposes.
This calculator, the weighted average, is general-purpose. It calculates weighted averages for any context, grades, statistics, finance, or anything else. It’s flexible: you can mix points, percents, and letters in the same calculation. It shows you the simple average alongside the weighted average so you can see the effect of weighting. Use this when you have values with weights, and you want to calculate a weighted average without any extra assumptions about what those values represent.
The weighted grade calculator is built specifically for academic grading. It is designed around how syllabi are written, categories with percentage weights that add to 100%. It has features like drop-lowest (for “drop your lowest quiz” policies) and normalize weights (for partial-grade calculations mid-semester). Use that calculator when you are working directly from a syllabus, and you want features tailored to grading.
Both calculate weighted averages, but the weighted grade calculator adds grading-specific features on top of the core math. If you are a student tracking your course grade, the weighted grade calculator is probably a better fit. If you’re doing a one-off weighted average calculation, whether it’s for grades or something else, this calculator is simpler and more flexible.
For full semester tracking with assignments, deadlines, and what-if scenarios, neither of these is the right tool. That is what the grade calculator is for.
FAQ: Weighted Average Calculator
What is the difference between a weighted average and a simple average?
A simple average treats all values equally, adds them up, and divides by the count. A weighted average assigns different weights to values, multiplying each value by its weight before averaging. The formula is: Weighted Average = Σ(value × weight) ÷ Σ(weights).
Do the weights need to add up to 100?
No. Weights are relative to each other, not absolute. If you enter weights of 10, 20, and 30, that produces the same result as 1, 2, and 3 because the ratios are the same. In academic grading, weights are often written as percentages that add to 100, but that is a convention, not a requirement.
Can I mix points, percentages, and letter grades in the same calculation?
Yes. Use the Type dropdown for each row. Set one row to Points (e.g., 85/100), another to Percent (e.g., 88%), and another to Letter (e.g., B+). The calculator converts everything to percentages based on your selected grading scheme, then does the weighted average.
What is the simple average shown in the result card?
The simple average is the unweighted mean of all your values; it treats every row equally, regardless of weight. It is displayed alongside the weighted average so you can see how much the weighting affected the result. If the weighted average is higher than the simple average, your higher-weighted values are pulling the average up.
How are letter grades converted to percentages?
Letter grades are converted based on the thresholds for the grading scheme you selected (US, UK, ECTS, or Australian). For example, in the US scheme with default thresholds, an A is 93%, a B+ is 87%, etc. You can click “Edit thresholds” to adjust these boundaries if your institution uses different cutoffs.
Can I use this calculator for non-grade-related weighted averages?
Yes. Weighted averages are used in statistics (weighted means), finance (portfolio returns), and other fields. Enter your values and weights regardless of context, and the calculator computes the weighted average. The letter grade and GPA outputs are only meaningful for academic grading; ignore them if you are calculating something else.
What does the “Range” in the result card show?
The range shows the lowest and highest values you entered. It is displayed as “Range: 78.00% – 92.00%” when your lowest value is 78%, and your highest is 92%. This gives you a quick sense of the spread in your data.
How many rows can I add?
There is no hard limit. Click “Add row” to create as many rows as you need. Most weighted average calculations have 3-10 items, but the calculator can handle more if needed.
What is the difference between this and the weighted grade calculator?
This calculator is general-purpose for any weighted average calculation. The weighted grade calculator is designed for academic grading, with syllabus-based features such as drop-lowest policies and weight normalization. If you are calculating a grade from a syllabus, use the weighted grade calculator. If you are doing a general weighted average, whether for grades or something else, use this one.
Does this calculator save my data?
No. The calculator runs entirely in your browser. Nothing you enter is stored unless you click a share button. If you refresh the page, your data is lost. Use the “Copy link” button to save your calculation as a shareable URL.
Related Tools
- Weighted Grade Calculator: For calculating grades specifically from syllabus categories. Includes drop-lowest policies, weight normalization, and grading-specific features. Use this when you are working from a syllabus with weighted categories.
- Grade Calculator: For tracking your full course grade across the semester with individual assignments, categories, and what-if scenarios. Use this for comprehensive semester-long grade tracking.
Weighted averages show up everywhere, in grades, statistics, finance, and any scenario where some values matter more than others. The math is the same regardless of context: multiply each value by its weight, add everything up, and divide by the total weight.
This calculator does that math for you. Enter your values in whatever format they come in, points, percentages, or letter grades, assign weights, and get both the weighted average and the simple average so you can see the difference.
No spreadsheets. No manual multiplication. Just the weighted average you need.