Weighted Average Calculator
Calculate weighted scores, grades, and values with step-by-step ratio derivations.
Enter Value & Weight Pairs
Weighted Average
87.00
Step-by-Step Derivation:
What is the Weighted Average Calculator?
The Weighted Average Calculator resolves datasets where certain values contribute more significantly to the final outcome than others. It is heavily used by teachers to grade classes (where a final exam is worth 40%) and by investors analyzing stock portfolios.
How It Works (Formula)
In a standard average, every number is equal. In a weighted average, every data point is multiplied by its specific "weight" (percentage). The calculator sums all these weighted products together, and divides by the total sum of the weights.
$$ W = \frac{\sum_{i=1}^{n} (x_i \times w_i)}{\sum_{i=1}^{n} w_i} $$
The formula for calculating an unbalanced, weighted mean.
How to Use It
For each item in your list, enter the numerical "Data Value" in the first box, and its corresponding "Weight" (like 25% or 0.25) in the second box. Add as many rows as needed. The tool will calculate the true proportional average.