What this result means
Calculate a weighted average from matching value and weight lists with an auditable weighted sum.
Weighted Average Calculator
Use the Weighted Average Calculator to calculate and interpret a weighted average from paired values and weights, not an unweighted arithmetic mean.
Weighted average
Enter your values, then calculate to see a verified result.
Reference range
How this result is calculated
A clear calculation path based on your inputs.
Inputs usedReview the information used for this result.
Full calculation and sourcesWeighted average = sum(value x weight) / sum(weights).
Versioned calculationFormula v1.0.1
Method used
Weighted average = sum(value x weight) / sum(weights).
Important limitation
The result is only as reliable as the inputs and stated method.
Enter the inputsUse values with the units and definitions shown beside each field.
Apply the methodWeighted average = sum(value x weight) / sum(weights).
Inspect the bridgeReview the primary result and supporting outputs before using it.
Check limitationsConfirm the assumptions, date, jurisdiction or population match your use case.
Interpretation
80 weighted 40 and 90 weighted 60 gives 86.
Weighted average = sum(value x weight) / sum(weights).
The result is only as reliable as the inputs and stated method.
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Report a calculation issue Weighted Average Calculator: purpose and method
Calculates weighted average, weighted sum, total weight, and pairs from values and weights with visible method, validation, precision, and limitations.
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Related calculators and resources
Method and test recordFormula v1.0.1
- Recorded scope
- Weighted Average Calculator formula, input validation, edge behavior and result presentation.
- Publisher
- CalculatorGeek
- Reviewed by
- CalculatorGeek Editorial Team
- Recorded review date
- 2026-09-21
- Next source review
- 2027-09-21
- Definition fixtures
- 1 configured scenarios
- Published examples
- 1 shown below
Recorded method
Package reconciliation, primary-source mapping, competitor feature comparison, deterministic fixtures, PHP/JavaScript parity and responsive preview QA.
These records describe the published model and reference tests. A test-case count is not a certification of every possible input or an independent specialist review. Editorial policy
Known limitations
- The result is only as reliable as the inputs and stated method.
- Changing legal, medical, exam or statistical conventions must be checked at the source.
Method sources
Latest model update
2026-09-21 -
Reference inputs and expected results
Up to 12 examples from the configured definition fixtures are shown. Expected values use the stated output units; invalid inputs are intended to be rejected.
| Case | Inputs | Expected result |
|---|---|---|
| Primary worked example | Values: 80, 90; Weights: 40, 60 | Weighted average: 86; Total weight: 100; Pairs: 2 (allowed numeric tolerance: 0.0001) |
Report an issue with this tool. Include the page URL, units, expected answer, and steps to reproduce. Do not include sensitive personal information.
On this page
Direct answer
Calculate a weighted average from matching value and weight lists with an auditable weighted sum. Each value contributes in proportion to its paired weight. Check the reported weighted sum, total weight, and pair count before interpreting the average.
Continue with the Arithmetic Mean Calculator when each observation should count equally.
Continue with the Descriptive Statistics Calculator when you also need measures of spread and quartiles.
Formula and methodology
Weighted average = sum(value x weight) / sum(weights).
Pair each value with one nonnegative weight. The denominator must be greater than zero; mismatched lists or an all-zero weight list return validation instead of an undefined number. Working precision is retained until the displayed result is rounded.
Worked example
For values 80 and 90 with respective weights 40 and 60, the weighted sum is (80 x 40) + (90 x 60) = 8,600. The total weight is 100, so 8,600 / 100 = 86 across two pairs.
The calculator retains working precision and rounds only the displayed values.
Interpret the result carefully
Method boundary: The result is only as reliable as the paired values, weights, and selected method. A weighted mean does not describe variability, establish causation, or decide whether the weighting policy is appropriate.
Inputs, mismatched-list validation, zero-total-weight behavior, working precision, and JavaScript/PHP parity are covered by deterministic release tests. Keep the unrounded value when this result feeds another calculation.
Inputs, outputs and result meaning
Calculates weighted average, weighted sum, total weight, and pairs from values and weights with visible method, validation, precision, and limitations.
Inputs
- Values
- Enter values in matching order.
- Weights
- Enter nonnegative weights in matching order.
Outputs
- Weighted average
- This is the primary result. The visible value uses up to 4 decimal places according to the output rule.
- Weighted sum
- The visible value uses up to 4 decimal places according to the output rule.
- Total weight
- The visible value uses up to 4 decimal places according to the output rule.
- Pairs
- The visible value is displayed without decimal places.
The calculator applies the documented method after validating and normalizing the inputs. Keep the result label, unit, selected mode, and stated limitations together when sharing the answer.
Frequently asked questions
What method does this calculator use?
Weighted average = sum(value x weight) / sum(weights).
How should I round the result?
Keep full precision during the calculation and round only the final display unless a governing standard says otherwise.
What is the main limitation?
The result is only as reliable as the inputs and stated method.
Can I reproduce the answer?
Yes. The formula, inputs, supporting outputs and worked example are displayed on the page.
Sources
CalculatorGeek rechecked the formula, example, validation boundaries, and source links on October 6, 2026. No specialist credential or official affiliation is claimed.