Weighted average calculator
Calculate an average when values have different weights, such as grades or quantities.
Private: it runs in your browser and what you type is never sent anywhere. How to check it
Separate value and weight with ;. Weights do not need to total 100.
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How we handle your data →How to use this tool
- Enter a semicolon-separated value and weight on each line.
- Calculate with nonnegative weights and at least one positive weight.
- Review the average and weight total; weights do not have to sum to 100.
An example you can verify
Combine two grades with different weights.
Example input
8;40 6;60
Expected result
Weighted average: 6.8. Rows: 2. Total weight: 100.
(8 × 40 + 6 × 60) ÷ (40 + 60) = 6.8. Weights of 4 and 6 give the same average.
Calculate an average with different weights
Enter value;weight on each row. Weights can be percentages or quantities and need not total 100. A zero-weight row contributes nothing; at least one weight must be positive.
Weighted average calculator: uses and practical guidance
Weighted average combines values that contribute differently to a collection. Each value is multiplied by its weight, then the sum of those products is divided by the total weight. It supports exercises involving scores with different contributions or groups of different sizes. Define what each weight represents before calculating so the average answers a specific question. A valid numeric result does not independently establish that the chosen weights suit the underlying problem.
Enter one value and weight pair per line, separated by a semicolon. Weights may be percentages or relative quantities; they need not total one hundred because the formula normalizes by their sum. Multiplying every weight by the same factor preserves the average. A zero weight contributes nothing and at least one weight must be positive. This model does not accept negative weights, so check signs when copying data into the input.
Do not combine incompatible value scales without conversion. A score out of ten and a score out of one hundred need comparable representation first. Weights describing overlapping or incompatible groups also require review. The calculator applies the numeric model but does not validate a rubric or the definition of a dataset. Keep an explanation of the weights with the data so someone else can assess the meaning of the calculation.
Check pair count, total weight and one simple manual example. Equal weights give the ordinary mean. With nonnegative weights, the average should lie between the smallest and largest contributing values. Mean, median and sum provides an unweighted summary. For journey speeds, establish the relevant base first: total distance and time are often necessary to interpret the appropriate combined average.
Settings and limits
Enter one value;weight pair per line, separated by a semicolon. For example, 8;40 and 6;60 give 6.8. Weights can be percentages, counts or proportions; they do not have to total 100. They must be nonnegative and at least one must be positive. Decimal commas, up to 10,000 rows and magnitudes up to 10 to the power of 100 are supported.
Frequently asked questions
Can values be negative or weights be zero?
Yes. Values may be negative. A zero weight contributes nothing to the average, but its row is still counted. Calculations use JavaScript floating-point arithmetic with display rounding.
Are my data stored on a server?
No. Content and files are processed in your browser without an account. Closing the page loses unsaved results.
Is it free, and do I need to sign up?
Yes, it is free. You do not need to sign up, create an account or install an app, and there is no daily quota: open the tool and use it. The only limits are file sizes, which protect your device’s memory.
Is my data sent to any server?
No. What you type or paste is processed in your browser’s memory and is not sent to any server. You can check it in the browser’s Network tab or by going offline after the page has loaded.