Statistics Calculator
Bar Chart
Results
How to Use This Calculator
Type your numbers separated by commas in the input field, then press Calculate. The tool finds the mean, median, mode, range, and standard deviation for your dataset. You can enter as few as 2 values or as many as you like. The bar chart updates to show the distribution of your data visually.
The Four Main Measures
Mean: Add all values and divide by how many there are. This is the arithmetic average.
Median: Sort the values from smallest to largest and pick the middle one. If there are two middle values, average them.
Mode: The value that appears most often. A dataset can have no mode, one mode, or several modes.
Range: Subtract the smallest value from the largest. This tells you how spread out the data is.
When to Use Which Measure
| Situation | Best Measure | Why |
|---|---|---|
| Test scores in a class | Mean | Data is usually evenly spread |
| Income or house prices | Median | Outliers like very high earners skew the mean |
| Most popular shoe size | Mode | You want the most common item, not an average |
| How consistent data is | Range or standard deviation | Measures how much values vary |
Calculating Mean Step by Step
Step 2: Count the values: there are 5.
Step 3: Divide: 40 / 5 = 8.
Mean = 8.
Median with Even vs Odd Counts
With an odd count: sort the values and take the exact middle one. For 3, 7, 9, 11, 15, the median is 9 (the 3rd of 5 values).
With an even count: sort the values and average the two middle ones. For 3, 7, 9, 11, the median is (7 + 9) / 2 = 8.
Common Mistakes to Avoid
- Forgetting to sort the data before finding the median. Order matters.
- Assuming the mean and median will always be close. Outliers can separate them widely.
- Thinking a dataset must have a mode. If no value repeats, there is no mode.
- Confusing range with standard deviation. Range uses only two values; standard deviation uses all of them.