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Average Calculator

Find the average (mean) of a list of numbers, or a weighted average where some values count more than others, such as course grades with different credit weights.

How it works Report a problem

Centroid Master

Multi-Dimensional Average & Balanced Metrics

About the Average Calculator

Find the average (mean) of a list of numbers, or a weighted average where some values count more than others, such as course grades with different credit weights.

How to use the Average Calculator

  1. Choose Simple List or Weighted Averages.
  2. For a simple average, enter your numbers separated by commas.
  3. For a weighted average, enter the values and their weights in the matching boxes.
  4. Press the calculate button to see the result.

Formula and method

Simple average: Mean = Σx ÷ n

Weighted average: Mean = Σ(w × x) ÷ Σw

Worked example

15, 22, 34, 5, 18 add up to 94; divided by 5 numbers the average is 18.8. For scores 80, 90 and 75 with weights 0.3, 0.5 and 0.2: 24 + 45 + 15 = 84.

Mean, median and mode. For 3, 5, 5, 7 and 10, the mean is 30 ÷ 5 = 6, the median (middle value) is 5 and the mode (most common) is 5.

When to use the Average Calculator

  • Finding the average of test scores, prices, temperatures or survey answers.
  • Checking whether one value is unusually high or low compared with the rest.
  • Summarising a set of measurements in a single number.

Common mistakes to avoid

  • Using the mean when a few extreme values distort it. In that case the median is a better summary.
  • Averaging percentages or rates that have different bases without weighting them.
  • Leaving out a value, or entering one twice, when copying data.

Tips

  • Weights do not have to add up to 1. The calculator divides by their sum.
  • A few extreme values can pull the mean up or down. Check the median too.

Frequently asked questions

What is the difference between mean, median and mode?
The mean is the arithmetic average, the median is the middle value when sorted and the mode is the most frequent value.
What is the difference between mean, median and mode?
The mean is the sum divided by the count. The median is the middle value when the numbers are sorted. The mode is the value that appears most often.
What is a weighted average?
An average in which some values count for more than others, such as course grades where an exam is worth more than homework.