Calculate Statistics from Any Dataset
Find mean, median, mode, range, variance, standard deviation, quartiles, and IQR. Includes box plot data and the 68-95-99.7 empirical rule.
How It Works
Mean = Σx / n, Median = middle value, Mode = most frequentThe mean is the arithmetic average (sum ÷ count). The median is the middle value when sorted. The mode is the most frequently occurring value. Range = max - min. Standard deviation measures how spread out the data is.
Quick Tips
Mean vs Median
Mean is affected by outliers; median is resistant. For skewed data, median is more representative.
No Mode
If all values appear equally often, there is no mode. Some datasets have multiple modes.
IQR
Interquartile Range (Q3-Q1) measures the spread of the middle 50% of data. Robust to outliers.
Std Dev
Standard deviation ≈ Range / 4 for roughly normal data (range rule of thumb).
Step-by-Step Instructions
- 1Enter your data as comma-separated numbers (e.g., 12, 15, 18, 22, 25).
- 2Click Calculate to see all statistics.
- 3Review the step-by-step solution for detailed calculations.
Frequently Asked Questions
When should I use mean vs median?▼
Use mean for symmetric data without outliers. Use median when data is skewed or has outliers — like income data where a few high earners pull the mean up but not the median.
What is standard deviation?▼
Standard deviation measures how spread out data is from the mean. Low std dev = data clustered near mean. High std dev = data widely spread. It's the square root of variance.
What is the 68-95-99.7 rule?▼
For normally distributed data: 68% falls within 1 standard deviation of the mean, 95% within 2, and 99.7% within 3. This is the empirical rule.