Weighted Average Calculator NZ
This calculator finds the weighted average of a set of values, where some values count for more than others according to their weights. An ordinary average treats every number equally, but in many real situations some figures deserve more influence than others, and that is exactly what a weighted average captures. It multiplies each value by its weight, adds those products, and divides by the total of the weights. The applications are everywhere: a course grade where the exam counts more than the quizzes, an investment portfolio return where each holding is weighted by its size, an average price paid across purchases of different quantities, or a survey result where some groups are weighted to match the population. Wherever the items being averaged are not equally important, the weighted average gives the honest figure. This tool makes it straightforward. You paste or type your values into one box and their matching weights into another, in the same order, and the calculator pairs them up, computes the weighted average, and also shows the simple unweighted average for comparison, the total weight, and the sum of the weighted products. The results update as you type, so you can adjust a weight and immediately see its effect. Use it for grades, portfolio returns, average costs, scoring models, or any situation with unequal importance. The weights can be any positive numbers, whether percentages, counts, dollar amounts or arbitrary points, since only their relative sizes matter. Just make sure you enter the same number of values and weights so each value has a weight to go with it. The result always lies between the smallest and largest of your values.
Weighted average = sum of (value x weight) / sum of weights. Enter the same number of values and weights. Weights can be any positive numbers.
How it works
Each value is multiplied by its matching weight, and those products are added together. That total is divided by the sum of all the weights to give the weighted average. Values with larger weights pull the result toward themselves, while the simple average ignores the weights and treats every value equally.
Worked example
For values 80, 90 and 70 with weights 2, 3 and 5, the products are 160, 270 and 350, which sum to 780. The total weight is 10, so the weighted average is 780 divided by 10, which is 78. The simple average is 80, higher because it ignores that the lowest value carries the most weight.
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