Free Statistics Calculator

Calculate mean, median, mode, standard deviation, and percentiles instantly. Detect outliers, view distribution chart. Free statistics calculator, no signup.

How to Use Free Statistics Calculator

  1. Enter your dataset as comma-separated or space-separated numbers in the input field
  2. View mean, median, mode, range, variance, and standard deviation calculated instantly
  3. Check Q1, Q2, and Q3 quartile values and review the automatic outlier detection results
  4. Read the distribution summary to understand how spread out your data set is

Frequently Asked Questions

What is the difference between mean, median, and mode?

Mean: average of all values (sum ÷ count). Median: middle value when sorted. Mode: most frequent value. Example: [1, 2, 2, 3, 100] — Mean=21.6, Median=2, Mode=2. For skewed data, median is often more representative.

What is standard deviation?

Standard deviation measures how spread out values are from the mean. Low SD = data clustered near the mean. High SD = data widely spread. Formula: square root of the average squared deviation from the mean.

What is an outlier in statistics?

An outlier is a value significantly different from other values. Common rule: values more than 1.5× the interquartile range (IQR) below Q1 or above Q3. Our calculator automatically identifies outliers in your data.

How do I enter data into the calculator?

Paste comma-separated numbers (e.g., 12, 45, 67, 23, 89) or space-separated. Our calculator handles both formats and ignores any extra spaces or formatting automatically.

What percentile means what?

The 50th percentile is the median — 50% of values are below it. The 90th percentile means you are higher than 90% of the data. The 25th (Q1) and 75th (Q3) percentiles define the middle 50% of the data (IQR).

What is the difference between population and sample standard deviation?

Population SD divides by N and is used when you have all data. Sample SD divides by N-1 and is used when your data is a sample from a larger group. Our calculator shows both values so you can use whichever is appropriate for your analysis.