FreeToolStation

Weighted Average Calculator

The weighted mean of any list of values and weights.

Education Calculators Free, no sign-up Runs in your browser

Name, value, weight. The name is optional.

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Weighted average
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Unweighted average
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Total weight
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Items
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Difference
ItemValueWeightShareContribution
Weights do not have to add up to 100. The weighted average divides by whatever the weights total, so 40/25/35 and 8/5/7 give exactly the same answer.

About the Weighted Average Calculator

Weighted Average Calculator takes a list of values with weights attached and returns the weighted mean. Each line is a name, a value and a weight; the name is optional and anything that is not a number is treated as one. It handles any number of items, which is the point -- the arithmetic is easy for three and tedious for fifteen.

A weighted average multiplies each value by its weight, adds the products, and divides by the total weight. Because of that last step the weights need no particular scale. Weights of 40, 25 and 35 give the same answer as 8, 5 and 7, and the share column shows what each weight works out to as a percentage of the total.

The unweighted average sits beside the weighted one for a reason: the gap between them tells you how much the weighting is doing. When they are close, the weights barely matter. When they are far apart, one heavily weighted item is driving the result, and the contribution column names it.

The page shows its working, not just its answer. Where there is a formula it is printed with your own numbers substituted in, so you can check the result rather than take it on trust -- which is the difference between a calculator you can use for something that matters and one you cannot.

Everything runs inside your browser. What you type is never uploaded, never logged and never stored, and the calculator keeps working if your connection drops after the page has loaded.

Looking for something this does not cover? FreeToolStation.com is a second collection of the same kind of everyday tools, and it is worth a look if weighted average calculator is only part of what you are working on.

How to use the Weighted Average Calculator

  1. Enter value and weight, one per lineDecimals are fine, and thousands separators are accepted and ignored.
  2. Read the weighted average, unweighted average and total weightThe figures update as you type. The Calculate button is there if you would rather press something, but nothing waits for it.
  3. Copy or check the resultCopy the summary with the copy button, or open the table to check it row by row. The download button saves it as a file.

Features

  • Shows weighted average, unweighted average, total weight, items and difference together, so you are not running it twice
  • A results table you can read across
  • Updates as you type, with no button to press and no page reload
  • Copy the result in one click
  • Download the detail as a .csv for a spreadsheet
  • Free, no sign-up, and it runs entirely in your browser

Who uses this tool

The weighted average calculator is used by writers, developers, students, marketers and anyone else who needs the job done once without installing software. Common cases include:

  • Working out a module grade from coursework and exams
  • Averaging survey scores with different sample sizes
  • Blending supplier prices by volume purchased
  • Combining scores from assessments of unequal value

Frequently asked questions

Do my weights have to add up to 100?

No. The calculator divides by whatever the weights total, so any consistent scale works.

What format should each line be in?

Name, value, weight -- separated by commas, semicolons or tabs. The name can be left out and the item will be numbered instead.

Why is the unweighted average shown?

As a reference point. The difference between the two shows how much the weighting changed the answer.

Can a weight be zero?

Yes, for an individual item -- it simply drops out. All of them cannot be zero, because then there is nothing to divide by.

If the weighted average calculator is not quite what you need, these other free tools solve closely related problems, and there are 8 more in education calculators.

Average Calculator

Paste any list of numbers and get the full set of summary statistics.

Math Calculators Use tool

GPA Calculator

Calculate weighted GPA from your grades and credit hours.

Education Calculators Use tool

Checked and rebuilt on 2026-10-14. The method this calculator uses is described in the section above, and corrections go through the contact page.