Quartiles & IQR Calculator
Calculate quartiles, interquartile range, detect outliers, and visualize data with box plots.
Enter numbers separated by commas (e.g., 1, 2, 3, 4, 5)
結果
値を入力して計算をクリックして結果を表示してください。
Theory & Formula
What are Quartiles?
Quartiles divide the data into four equal parts. They help identify the distribution and spread of data.
The Three Quartiles
• Q1: Q1: 25th percentile (25% of data below this value)
• Q2: Q2: 50th percentile (median, 50% of data below this value)
• Q3: Q3: 75th percentile (75% of data below this value)
Interquartile Range (IQR)
\(IQR = Q_3 - Q_1\)
IQR measures the spread of the middle 50% of data
Outlier Detection
Values outside 1.5 × IQR from Q1 or Q3 are considered outliers
\(\text{Lower bound} = Q_1 - 1.5 \times IQR\)\(\text{Upper bound} = Q_3 + 1.5 \times IQR\)