Weighted Average Calculator
Enter each value with its weight. The calculator multiplies, adds and divides by the total weight to give the weighted mean.
Result
- Sum of value × weight
- 500
- Sum of weights
- 6
- Unweighted average
- 80
Formula
- Weighted average = Σ (value × weight) ÷ Σ weights
How the Weighted Average Calculator works
In a weighted average, some values count for more than others. Multiply each value by its weight, add the products, and divide by the sum of the weights. If all weights are equal, the result is the ordinary mean.
Weights can be credit hours, quantities, percentages or any measure of importance. They do not need to add up to 1 or 100, because the formula divides by their total.
Worked example
Values 90, 80 and 70 with weights 3, 2 and 1: (90 × 3 + 80 × 2 + 70 × 1) ÷ (3 + 2 + 1) = 500 ÷ 6 = 83.33. The plain average of the three values would be 80.
Frequently asked questions
When should I use a weighted average?
Whenever items contribute unequally: course grades with different credit hours, an average price paid across purchases of different sizes, or survey results from groups of different sizes.
Do the weights have to add up to 100?
No. Any positive weights work, because the sum of the weights is divided out.
Related calculators
- Average CalculatorCalculate the average (mean) of a list of numbers, with the sum, count, median, mode, range and geometric mean.
- Grade CalculatorCalculate your weighted course grade from assignment scores and their weights. Shows the percentage, letter grade and remaining weight.
- GPA CalculatorCalculate high school or college GPA on the 4.0 scale from letter grades and credits. Supports weighted honors and AP classes and cumulative GPA.
- Ratio CalculatorSimplify a ratio, solve for a missing value in A : B = C : D, or split a total in a given ratio. Works with whole numbers and decimals.
- Proportion CalculatorSolve a proportion a/b = c/d for the missing value by cross-multiplication. Enter any three of the four numbers.
- Factor CalculatorFind all factors of a number, its factor pairs and its prime factorization. Also tells you whether the number is prime.
- GCF Calculator (Greatest Common Factor)Find the greatest common factor of two or more numbers, with the Euclidean algorithm steps and prime factorizations. Also gives the LCM.
- LCM Calculator (Least Common Multiple)Find the least common multiple of two or more numbers, with prime factorizations. Also gives the greatest common factor.
- Rounding CalculatorRound a number to the nearest whole number, tenth, hundredth, thousandth, ten, hundred or thousand. Exact decimal rounding with no floating point errors.
- Significant Figures CalculatorCount the significant figures in a number and round it to any number of significant figures, with scientific notation.
- Modulo CalculatorCalculate a mod n, the remainder after division, with the quotient. Handles negative numbers under both the mathematical and programming conventions.
Related unit converters
Calculations run in your browser and nothing you enter is sent to a server. Results are provided for general information. Check critical figures independently before relying on them.