Mean Absolute Deviation Calculator
Enter a data set to calculate the mean and the average absolute distance of every value from that mean.
Enter Your Data
Results
Count (n)
8
Mean
18.0000
Mean Absolute Deviation
4.5000
| Value | Deviation from Mean | Absolute Deviation |
|---|---|---|
| 10 | -8.0000 | 8.0000 |
| 12 | -6.0000 | 6.0000 |
| 23 | 5.0000 | 5.0000 |
| 23 | 5.0000 | 5.0000 |
| 16 | -2.0000 | 2.0000 |
| 23 | 5.0000 | 5.0000 |
| 21 | 3.0000 | 3.0000 |
| 16 | -2.0000 | 2.0000 |
Absolute Deviation per Value
How the Mean Absolute Deviation Calculator Works
This tool finds the mean of your data, then measures how far each value is from that mean, ignoring direction. Averaging those absolute distances gives the mean absolute deviation, a simple way to describe how spread out a data set is without squaring the differences.
Formula
Mean = sum of values / count. Mean Absolute Deviation = sum of |value - mean| / count.
Example
For the data set 2, 4, 6, 8, 10, the mean is 6. The absolute deviations are 4, 2, 0, 2, 4, and their average, the MAD, is 2.4.
Limitations
MAD treats every deviation with equal weight and does not square differences, so it responds differently to outliers than standard deviation. It is best used alongside, not instead of, other spread measures like standard deviation or range.
How to use the result responsibly
- Check that every input uses the unit and time period shown beside the field.
- Compare the result with the worked example and formula above.
- For financial, tax, health, or legal decisions, confirm current rules with a qualified professional or the relevant authority.
Frequently Asked Questions
How is MAD different from standard deviation?
Standard deviation squares each deviation before averaging and taking a square root, which weights larger deviations more heavily. MAD simply averages the absolute distances, so it is less sensitive to extreme outliers.
What does a MAD of 0 mean?
A MAD of 0 means every value in the data set is identical to the mean, so there is no spread at all.
Editorially reviewed September 22, 2026. Read our calculation methodology and editorial policy.