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Average Calculator mean or weighted

Paste a list to get its mean, or add weights to find a weighted average such as a course grade.

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Answer

Enter your numbers or pick an example — the answer and the steps appear here instantly.

Two kinds of average

  • Mean of a list

    Add the values and divide by how many there are. The result shows the sum, the count and the mean as an exact fraction plus its decimal.

  • Weighted average

    Enter values and weights in the same order. Each value is multiplied by its weight, and the total is divided by the sum of the weights.

  • Weights on any scale

    Weights do not have to add up to 100: 2, 3, 5 works as well as 20, 30, 50, because only their proportions matter.

  • Mismatches caught

    If the two lists have different lengths, the calculator stops and tells you, instead of pairing values with the wrong weights.

How to calculate an average here

  1. Choose mean or weighted

    A plain mean needs only the numbers; a weighted average also needs one weight per number.

  2. Enter the numbers

    Up to 500 values, separated by commas or spaces. Fractions and decimals are accepted.

  3. Add weights if needed

    Type the weights in the second box in exactly the same order as the values they belong to.

  4. Calculate and copy

    The result card shows the average and the working behind it. Copy it, or ask the AI Math Solver to explain it.

How to work out a weighted average by hand

A plain mean treats every value equally: the mean of 85, 92, 78 and 90 is 345/4 = 86.25. A weighted average lets some values count more. Multiply each value by its weight, add the products, and divide by the sum of the weights.

Suppose homework is worth 20%, quizzes 30%, the midterm 25% and the final 25%, with scores 85, 92, 78 and 90. The products are 1,700, 2,760, 1,950 and 2,250, which sum to 8,660; dividing by the total weight of 100 gives 86.6.

If the weights do not add to 100, the method is unchanged; you just divide by whatever they do add to. Credit hours work the same way: a 4-credit course graded 3.0 and a 3-credit course graded 4.0 average to (12 + 12)/7 = 24/7 ≈ 3.43.

A common slip is averaging averages. Two classes with means of 80 and 90 do not have a combined mean of 85 unless they are the same size; weight each class mean by its number of students to get the right figure.

Frequently asked questions

In everyday use they are the same thing: the sum divided by the count. Statisticians sometimes use average more loosely to cover the median or mode as well, so this calculator labels its result as the mean.

No. Any positive weights work, because the calculator divides by their total. Weights of 1, 1 and 2 give the third value twice the influence of each of the others.

The mean is kept exact, so 345/4 appears alongside 86.25. When the decimal never ends, as with a mean of 10/3, the decimal is rounded and marked ≈ while the fraction stays exact.

You can average up to 500 values in one calculation. For larger data sets, a spreadsheet's AVERAGE function is a better fit.

Yes, and it works without an account because the math runs in your browser. The one metered extra is the AI explanation: it is included in the Pro plans* (*fair use: up to 300 runs a day across the writing, study and code tools), uses 2 credits without a plan, and offers signed-out visitors a free preview of its start.

Yes, as long as you enter the weights from your syllabus. Treat the result as an estimate to compare with your school's official grade, and if you use the AI explanation for assignments, follow your course's rules; it can contain mistakes.

Other number tools

Find your average

A plain mean or a weighted grade, with the sum and the exact fraction shown.

Calculate the average
  • Mean and weighted modes
  • Exact fraction plus decimal
  • Weights on any scale