±Free
IQR outlier detector
Flag values beyond Q1 − 1.5 IQR and Q3 + 1.5 IQR using interpolated quartiles.
Enter at least four observations. The calculator sorts them, obtains interpolated quartiles at 25% and 75%, then flags values below Q1 − 1.5 IQR or above Q3 + 1.5 IQR.
How to use
- Enter your text, values, or image.
- Adjust the options and run the tool.
- Copy or download your result.
Worked example
Example input
Numbers: 1,2,3,4,100
Example result
{
"q1": 2,
"q3": 4,
"iqr": 2,
"lowerFence": -1,
"upperFence": 7,
"outliers": [
100
]
}Limitations and details
The rule flags unusual values rather than proving errors; quartile conventions may differ, and flagged values are returned in sorted order.
Inputs and options
- Numbers
- Text
Frequently asked questions
Is this tool free and private?
Yes. All 300 tools are free in this phase. Processing happens in your browser; your input and files are not sent to our servers.