Average Calculator
This average calculator finds the mean, median, mode, count, sum, and range of a list of numbers. Paste or type the numbers separated by commas or spaces and the average calculator returns them all at once. Add a weight for each number and it becomes a weighted average calculator, for grades, prices, or scores that do not count equally.
Results
The Average Calculator is part of our Statistics & Probability collection. Browse more statistics & probability to size, convert, and check your work alongside this tool.
What the average calculator shows
The average, or arithmetic mean, is the sum of the numbers divided by how many there are. The average calculator gives the mean along with the median (the middle value) and the mode (the most common value), because each tells you something different about the data. With weights, it finds a weighted average, where some numbers count more than others.
Mean calculator formulas
The median is the middle value after sorting, or the average of the two middle values when the count is even. The mode is the value that appears most often; a list where every value appears once has no mode.
Average calculator example
For 12, 15, 9, 21, 15:
For a weighted average of exam scores 85, 90, and 78 with weights 30, 50, and 20 percent, the weighted average is 86.1, compared with a plain average of 84.33.
How to use the average finder
Type or paste your numbers separated by commas, spaces, or new lines. The average finder returns the mean, median, mode, count, sum, and range. For a weighted average, enter one weight for each number in the weights field, in the same order; the tool then returns the weighted average and the plain average for comparison.
Reading the arithmetic mean calculator results
The mean uses every value, so a single extreme number can pull it far from the typical value; the median resists that. When mean and median are close, the data is roughly balanced. Use the weighted average whenever items carry different importance, such as course credits, portfolio shares, or survey groups of different sizes.
When to find the mean
- Averaging test scores with the average score calculator
- Finding a weighted grade from coursework weights
- Summarising measurements or survey data
- Checking the typical value in a data set
Common average calculator mistakes
- Averaging percentages of different bases. Weight them by size.
- Using the mean with big outliers. Check the median too.
- Mismatched weights. Give exactly one weight per number.
Tips for accurate results
- Paste data straight from a spreadsheet column.
- Compare mean and median to spot skew.
- Keep weights in the same order as the values.
- See the weighted average examples for grades, prices, and forecasts.
- To keep the data in a sheet, build a weighted average in Google Sheets.
Compute weighted average for grades and prices
A weighted average gives some values more influence. In a course where the exam is worth 50 percent, coursework 30 percent, and a project 20 percent, multiply each score by its weight, add the results, and divide by the total weight. Weights do not need to add to 100; the formula divides by their sum, so 3, 5, and 2 give the same answer as 30, 50, and 20. Averages of fractions or ratios sometimes need exact arithmetic first, which the fraction calculator handles.
Average percentage calculator caution
Averaging percentages directly is only fair when each percentage is based on the same total. If groups differ in size, use their sizes as weights, or add the raw counts first and then work out one overall percentage.
Mean calculator: mean, median, and mode compared
| Data | Mean | Median | Mode |
|---|---|---|---|
| 12, 15, 9, 21, 15 | 14.4 | 15 | 15 |
| 1, 2, 3, 4 | 2.5 | 2.5 | None |
| 2, 3, 3, 4, 100 | 22.4 | 3 | 3 |
| 5, 5, 5, 5 | 5 | 5 | 5 |
Average Calculator FAQ
How do I calculate the average?
Add the numbers and divide by how many there are.
What is a weighted average?
An average where each value is multiplied by its weight before adding, then divided by the total of the weights.
What is the difference between mean and median?
The mean is the arithmetic average; the median is the middle value, which outliers do not distort.
Can a data set have no mode?
Yes, if every value appears the same number of times.