Weighted Average Calculator

Multiply each value by its weight, add those products to get the weighted sum, then divide by the total of the weights. For 90 at weight 30 and 80 at weight 70 the weighted sum is 8300, the total weight is 100, and the weighted mean is 83.

A plain average treats every value equally. A weighted average lets some values count more, so a final exam worth 70 percent moves the result far more than a quiz worth 30 percent. When all the weights are equal, the weighted mean matches the plain average.

No. Weights can be any non-negative numbers because the tool divides by their total. Weights of 30 and 70 give the same answer as 3 and 7, and credit hours of 4 and 3 work just as well as percentages.

Yes. Enter each grade or grade point as the value and its category weight or credit hours as the weight, then read the weighted mean. Homework, a midterm and a final with different weights combine into your overall course result.

A row with a weight of zero contributes nothing to the weighted sum and nothing to the total weight, so it is effectively ignored. That is a handy way to keep an item on screen while excluding it from the average.

A weighted average needs a positive total weight, so if every weight is zero the tool cannot compute a result and shows nothing. Give at least one item a weight above zero to see an answer.

Values can be any finite number, including decimals and negatives. Weights must be zero or positive, since a negative weight has no meaning as a share of the total and is rejected by the calculator.

The weighted mean, weighted sum and total weight are each rounded to six decimal places, which is enough for grades, finance and survey work while keeping the display readable.

Yes. Every calculation runs locally in your browser, so the numbers you type are never uploaded or stored on a server.