Weighted Average Calculator

A weighted average accounts for the proportional relevance of each component rather than treating all values equally. Unlike a simple average where every number counts the same, a weighted average gives more influence to values with higher weights. It is used in calculating final course grades where exams carry more weight than homework, computing blended investment returns across positions of different sizes, determining inventory cost averages, and many other analytical contexts. Enter two values with their corresponding weights to get the proportional result instantly. Weights can be expressed as decimals (0.4 and 0.6), whole-number percentages (40 and 60), or raw magnitudes like dollar amounts or population counts — the calculator normalizes them automatically by dividing by their sum, so the scale of the weights does not need to match any particular convention. This flexibility makes the calculator suitable for finance, education, statistics, and any field where components contribute unequally to an overall result and a simple arithmetic mean would misrepresent the true aggregate.

The calculator multiplies each value by its corresponding weight, sums those products, then divides the total by the sum of all weights: weighted average = (value1 × weight1 + value2 × weight2) ÷ (weight1 + weight2). Dividing by the actual total weight — rather than assuming 1 or 100 — ensures correct proportional results even when weights are arbitrary numbers like dollar amounts, item counts, or population sizes. If the weights sum to 1, the formula is the classic weighted mean. If they sum to 100, the denominator effectively normalizes to percentages. For unequal or unusual weight totals, the division still yields the correct proportional average. A weight of zero causes that value to be excluded entirely from the result, which is useful when one component has not yet been scored or counted.