Do weights need to add up to 100?

No. Weights describe relative importance. The calculation divides the weighted sum by the total weight. Weights 2, 3, and 5 produce the same average as 20, 30, and 50.

Can I use zero or negative weights?

Zero weights exclude a value from the weighted contribution. At least one weight must be positive. This calculator rejects negative weights and requires one weight for every value.

Does this calculate a specific exam or GPA score?

It calculates a general weighted mean. Enter the weights and values required by your own scoring rules. It does not supply exam coefficients, grade conversions, rounding rules, or institutional requirements.

Weighted Average Calculator

Tool workspace

Ready

Your input stays in this browser.

Run the tool when your input is ready.

Input

Add your source and choose the required options.

Values

Weights

Ready for a result

Run the tool to create the result.

Direct answer

What Weighted Average Calculator does

A weighted average multiplies each value by its weight, adds those contributions, and divides by the total weight. It gives greater influence to values with larger weights. Every value needs a corresponding nonnegative weight.

Output

What you receive

The result shows the weighted average, number of value-weight pairs, and total weight.

Use this tool

How to calculate a weighted average

Enter your values in their intended order.
Enter one weight for each value in the same order.
Select Calculate and inspect the weighted average, count, and total weight.

Processing

Calculate in your browser

The calculator processes your values locally. It does not send them to a calculation service.

Worked example

Test Weighted Average Calculator with a safe sample

Input: Values: 80, 90, 100. Weights: 20, 30, 50.

Settings: Match each weight to the value in the same position.

Expected result

Weighted average 93; total weight 100; count 3.

The contributions are 1600, 2700, and 5000. Their sum 9300 divided by 100 equals 93.

Limits

Check before you use the result

Enter up to 1000 values separated by commas, spaces, line breaks, or semicolons. Use a dot for decimal fractions.
Each nonzero input must have absolute value from 1e-100 through 1e100. Commas separate values, not thousands: 1,000 means two values. Fraction expressions and percentages are not accepted.
Calculations use floating-point numbers. Results can include rounding; closely spaced large integers can become indistinguishable during parsing.
Negative weights are not supported. At least one weight must exceed zero.
This tool does not determine official exam weights, GPA mappings, or grading rules.

Topics

Explore connected categories

Numbers, Units & Calculators