Statistics Calculator

Q: What is the difference between Sample and Population?

Choose Sample when your data is a small part of a bigger group. Choose Population when your data includes every value in the group. Sample divides by n − 1 when finding variance. Population divides by n . This changes the standard deviation and variance results.

Q: How many data points do I need to enter?

You need at least 1 value for basic stats like the mean. You need at least 2 values for standard deviation and t-tests. You need at least 3 values for normality tests and correlation. More data gives more reliable results.

Q: How does the keypad entry mode work?

Switch to Keypad Entry to tap in one number at a time using the on-screen buttons. Type each digit, then press ADD to put it into your dataset. Each value shows up as a chip that you can remove by clicking the × button. Press C to clear your current entry or CAD to erase all data.

Q: What does the geometric mean tell me?

The geometric mean (GM) is a type of average that works well for rates, percentages, and data that grows over time. It multiplies all the values together and takes the nth root. It only works when all values are greater than zero . If any value is zero or negative, the geometric mean is undefined.

Q: How do I read the frequency table?

The frequency table lists each unique value in your data. Frequency (f) shows how many times it appears. Relative (%) shows that count as a percent of all values. Cumulative adds up the frequencies as you move down the list.

Q: What do skewness and kurtosis numbers mean in practice?

A skewness near 0 means your data is balanced. A positive skewness means it has a long tail to the right. A negative skewness means a long tail to the left. A kurtosis near 0 means tails similar to a normal bell curve. Positive kurtosis means heavier tails. Negative kurtosis means lighter tails.

Q: How do I change the number of decimal places in my results?

Use the Decimals dropdown at the top of the Data Input Panel. You can pick 2, 3, 4, 5, 6, 8, or 10 decimal places. The default is 4. All results, tables, and charts update to match your choice.

Q: Which normality test should I use?

Shapiro-Wilk is best for small to medium datasets (under 50 values). Kolmogorov-Smirnov compares your data to a perfect bell curve and works for larger samples. Anderson-Darling focuses on the tails of the distribution. If you are unsure, check all three. If most agree, you can trust the result.

Statistics Calculator

Updated Jul 1, 2026 By Jehan Wadia

Introduction

This free statistics calculator helps you find the mean, median, mode, standard deviation, variance, and more from any set of numbers. Just type your data, press calculate, and get results right away. The tool shows each step of the math so you can follow along and learn how the answers are found.

Beyond basic stats, this calculator also builds charts like histograms, box plots, and Q-Q plots so you can see the shape of your data. It runs normality tests to check if your data follows a bell curve. You can perform hypothesis tests such as t-tests, ANOVA, chi-square, Mann-Whitney, Wilcoxon, and binomial tests. There are also built-in tools for Pearson and Spearman correlation, linear regression, and logistic regression. A confidence interval calculator and p-value calculator are included as well.

Whether you are a student working on homework or a researcher checking numbers, this calculator gives you fast, accurate results with clear explanations. Enter your data below to get started.

How to Use Our Statistics Calculator

Enter your numbers and this calculator will give you descriptive statistics, charts, normality tests, hypothesis tests, correlation, and regression results all at once.

Data Entry Method: Pick how you want to type in your data. Choose "Textarea Entry" to paste or type a list of numbers. Choose "Keypad Entry" to tap in one number at a time using the on-screen buttons.

Your Dataset: Type your numbers into the text box. You can separate them with commas, spaces, or line breaks. The calculator will find each number on its own.

Data Type: Select "Sample" if your data is a subset of a larger group. Select "Population" if your data includes every value in the group. This changes how variance and standard deviation are calculated.

Decimals: Pick how many decimal places you want in your results. The default is 4, but you can choose anywhere from 2 to 10.

Confidence Level: Choose 90%, 95%, or 99% to set how confident you want the confidence interval for the mean to be. A higher level gives a wider range.

Histogram Bins: On the Visualization tab, drag the slider to change how many bars the histogram uses. More bins show finer detail. Fewer bins show broader patterns.

Normality Tests: On the Normality tab, pick a significance level (α) of 0.01, 0.05, or 0.10. The calculator runs three tests to check if your data follows a normal (bell curve) shape.

Hypothesis Testing: On the Hypothesis Testing tab, choose a test from the dropdown menu. Fill in the required fields like the hypothesized mean, alpha level, and tail direction. Then press "Run Test" to see the test statistic, p-value, and whether to reject the null hypothesis.

Correlation: On the Correlation tab, enter matched pairs of numbers into the X and Y boxes. Press "Compute Correlations" to get the Pearson r, Spearman rho, covariance, and a scatter plot with the line of best fit.

Regression: On the Regression tab, enter your predictor values in X and response values in Y. Press "Run Linear Regression" to get the regression equation, R², residuals table, and fitted-value charts. You can also run a logistic regression if your outcome variable is binary (0 or 1).

Calculate Button: Press the blue "Calculate" button to run all descriptive statistics, charts, and normality tests on your main dataset. Press "Reset" to clear everything and start over.

What Is a Statistics Calculator?

A statistics calculator is a tool that takes a set of numbers and finds useful facts about them. Instead of doing math by hand, you enter your data and get answers right away. This calculator handles everything from simple averages to advanced tests used by scientists and researchers.

What Is Statistics?

Statistics is a branch of math that helps you understand data. Data is just a collection of numbers or facts. Statistics gives you ways to summarize that data, spot patterns, and make decisions based on what the numbers show. It is used in science, school, sports, medicine, business, and everyday life.

Key Concepts This Calculator Covers

Descriptive Statistics

Descriptive statistics summarize your data with a few key numbers. The mean is the average. The median is the middle value when your data is sorted. The mode is the value that shows up the most. Standard deviation tells you how spread out your numbers are from the mean. A small standard deviation means the values are close together. A large one means they are spread far apart.

Quartiles and Interquartile Range

Quartiles split your sorted data into four equal parts. Q1 is the 25th percentile, Q2 is the median, and Q3 is the 75th percentile. The interquartile range (IQR) is Q3 minus Q1. It measures the spread of the middle half of your data and helps find outliers.

Skewness and Kurtosis

Skewness tells you if your data leans to the left or right. A skewness of zero means the data is balanced. Kurtosis tells you if your data has heavy or light tails compared to a normal distribution. These two measures describe the shape of your data.

Confidence Intervals

A confidence interval gives you a range where the true average of a whole group likely falls. A 95% confidence interval means that if you repeated your study 100 times, about 95 of those intervals would contain the true mean. Choosing the right sample size helps make your confidence interval narrower and your results more precise.

Normality Tests

Many statistical tests assume your data follows a normal distribution, which looks like a bell curve. Normality tests like Shapiro-Wilk, Kolmogorov-Smirnov, and Anderson-Darling check whether your data fits that shape. If it does not, you may need to use different tests. You can also use a Z score calculator to see how far individual data points fall from the mean in terms of standard deviations.

Hypothesis Testing

Hypothesis testing helps you decide if a result is real or just due to chance. You start with a null hypothesis (H₀), which usually says there is no effect or no difference. You then calculate a p-value. If the p-value is smaller than your chosen cutoff (usually 0.05), you reject H₀ and conclude the result is statistically significant. This calculator supports t-tests, chi-square tests, ANOVA, Mann-Whitney, Wilcoxon, and binomial tests. You can also use a critical value calculator to find the threshold for rejecting H₀ and an effect size calculator to measure how large the observed difference is.

Correlation

Correlation measures how two variables move together. The Pearson correlation (r) ranges from −1 to 1. A value near 1 means both variables increase together. A value near −1 means one goes up while the other goes down. A value near 0 means there is no linear relationship. Spearman's rank correlation works the same way but uses ranks instead of raw values, making it better for non-linear patterns.

Regression

Linear regression finds the best straight line through your data points. It gives you an equation in the form ŷ = b₀ + b₁x, where b₀ is the intercept and b₁ is the slope. R² tells you how much of the variation in Y is explained by X. Logistic regression is used when the outcome is binary (yes/no, 0/1) and predicts the probability of an event happening.

Formulas used

Sample Mean

\bar{x} = \frac{\sum_{i=1}^{n} x_i}{n}

Sample Variance

s^2 = \frac{\sum_{i=1}^{n}(x_i - \bar{x})^2}{n - 1}

Standard Deviation

s = \sqrt{s^2}

One-Sample t-Statistic

t = \frac{\bar{x} - \mu_0}{s \div \sqrt{n}}

Confidence Interval for the Mean

\bar{x} \pm t_{\alpha/2,\, n-1} \cdot \frac{s}{\sqrt{n}}

Pearson Correlation Coefficient

r = \frac{\sum (x_i - \bar{x})(y_i - \bar{y})}{\sqrt{\sum (x_i - \bar{x})^2 \cdot \sum (y_i - \bar{y})^2}}

Linear Regression Slope and Intercept

b_1 = \frac{\sum (x_i - \bar{x})(y_i - \bar{y})}{\sum (x_i - \bar{x})^2}, \quad b_0 = \bar{y} - b_1\bar{x}

Chi-Square Goodness-of-Fit

\chi^2 = \sum_{i=1}^{k} \frac{(O_i - E_i)^2}{E_i}

Frequently asked questions

What types of numbers can I enter into the statistics calculator?

You can enter whole numbers, decimals, and negative numbers. The calculator accepts values like 42, 3.14, -7, and scientific notation like 1e3 (which means 1000). It ignores any text or letters that are not numbers.

How do I separate my numbers when typing them in?

You can use commas, spaces, line breaks, or any mix of these. For example, 10, 20, 30 and 10 20 30 both work the same way. The calculator finds each number on its own no matter which separator you use.

What is the difference between Sample and Population?

Choose Sample when your data is a small part of a bigger group. Choose Population when your data includes every value in the group. Sample divides by n − 1 when finding variance. Population divides by n. This changes the standard deviation and variance results.

How many data points do I need to enter?

You need at least 1 value for basic stats like the mean. You need at least 2 values for standard deviation and t-tests. You need at least 3 values for normality tests and correlation. More data gives more reliable results.

How does the keypad entry mode work?

Switch to Keypad Entry to tap in one number at a time using the on-screen buttons. Type each digit, then press ADD to put it into your dataset. Each value shows up as a chip that you can remove by clicking the × button. Press C to clear your current entry or CAD to erase all data.

What does the geometric mean tell me?

The geometric mean (GM) is a type of average that works well for rates, percentages, and data that grows over time. It multiplies all the values together and takes the nth root. It only works when all values are greater than zero. If any value is zero or negative, the geometric mean is undefined.

How do I read the frequency table?

The frequency table lists each unique value in your data. Frequency (f) shows how many times it appears. Relative (%) shows that count as a percent of all values. Cumulative adds up the frequencies as you move down the list.

What do skewness and kurtosis numbers mean in practice?

A skewness near 0 means your data is balanced. A positive skewness means it has a long tail to the right. A negative skewness means a long tail to the left. A kurtosis near 0 means tails similar to a normal bell curve. Positive kurtosis means heavier tails. Negative kurtosis means lighter tails.

How do I change the number of decimal places in my results?

Use the Decimals dropdown at the top of the Data Input Panel. You can pick 2, 3, 4, 5, 6, 8, or 10 decimal places. The default is 4. All results, tables, and charts update to match your choice.

Which normality test should I use?

Shapiro-Wilk is best for small to medium datasets (under 50 values). Kolmogorov-Smirnov compares your data to a perfect bell curve and works for larger samples. Anderson-Darling focuses on the tails of the distribution. If you are unsure, check all three. If most agree, you can trust the result.

What does the p-value mean in hypothesis testing?

The p-value tells you how likely it is to see your result if the null hypothesis were true. A small p-value (usually below 0.05) means the result is unlikely due to chance alone, so you reject the null hypothesis. A large p-value means you do not have enough evidence to reject it.

What is the difference between a one-tailed and two-tailed test?

A two-tailed test checks for a difference in either direction (higher or lower). A left-tailed test checks only if the value is less than expected. A right-tailed test checks only if it is greater. Use two-tailed when you do not know which direction to expect.

When should I use Welch's t-test instead of a pooled t-test?

Use Welch's t-test when you think the two groups have different amounts of spread (unequal variances). It is the safer choice and is on by default. Use the pooled t-test only when you are confident both groups have roughly equal variances.

What is the difference between Pearson and Spearman correlation?

Pearson r measures the straight-line (linear) relationship between two variables using the raw values. Spearman ρ ranks the values first, then measures the relationship. Use Spearman when your data has outliers, is not normally distributed, or follows a curved pattern.

What does R-squared mean in regression?

R² (R-squared) tells you what percentage of the change in Y is explained by X. An R² of 0.85 means 85% of the variation in Y can be explained by the regression line. The closer R² is to 1, the better the line fits your data.

When should I use logistic regression instead of linear regression?

Use logistic regression when your outcome (Y) has only two possible values, like 0 or 1, yes or no, pass or fail. Linear regression is for outcomes that can be any number. Logistic regression predicts the probability that the outcome equals 1.

How do I read the box plot?

The box shows the middle 50% of your data (from Q1 to Q3). The line inside the box is the median. The whiskers stretch to the smallest and largest values that are not outliers. Any dots outside the whiskers are outliers, which are unusually high or low values.

What is the Q-Q plot used for?

A Q-Q plot compares your data to a perfect normal distribution. If the dots fall close to the red reference line, your data is roughly normal. If the dots curve away from the line, your data does not follow a bell curve shape.

Can I use this calculator for paired data?

Yes. Go to the Hypothesis Testing tab and select Paired-Samples t-Test. Enter your two sets of matched values in the Condition 1 and Condition 2 boxes. Both sets must have the same number of values. You can also use the Wilcoxon Signed-Rank test for paired data that is not normally distributed.

What is the Mann-Whitney U-Test used for?

The Mann-Whitney U-Test compares two independent groups when your data is not normally distributed. It is a non-parametric alternative to the two-sample t-test. It uses ranks instead of raw values to decide if the two groups differ.

How does the Chi-Square Goodness-of-Fit test work?

This test checks if observed counts match what you expect. Enter your observed frequencies (the counts you actually got). Then either assume an equal distribution or enter your own expected frequencies. The test tells you if the difference between observed and expected is large enough to be statistically significant.

What does the odds ratio mean in logistic regression?

The odds ratio (OR) tells you how much the odds of the outcome change for each one-unit increase in X. An OR of 2 means the odds double. An OR of 0.5 means the odds are cut in half. An OR of 1 means X has no effect on the outcome.

Is my data saved or sent to a server?

No. All calculations run directly in your web browser using JavaScript. Your data is never sent to any server and is not saved anywhere. When you close or refresh the page, your data is gone.

Can I compare more than two groups at once?

Yes. Use the One-Way ANOVA test on the Hypothesis Testing tab. You can add as many groups as you need by clicking the Add Group button. ANOVA tells you if at least one group mean is different from the others.

What is the confidence interval telling me?

The confidence interval gives a range of values that likely contains the true mean of the whole group. A 95% confidence interval means you can be 95% sure the true mean falls within that range. A wider interval means less precision. A narrower one means more precision.

Introduction

How to Use Our Statistics Calculator

What Is a Statistics Calculator?

What Is Statistics?

Key Concepts This Calculator Covers

Descriptive Statistics

Quartiles and Interquartile Range

Skewness and Kurtosis

Confidence Intervals

Normality Tests

Hypothesis Testing

Correlation

Regression

Formulas used

Frequently asked questions

What types of numbers can I enter into the statistics calculator?

How do I separate my numbers when typing them in?

What is the difference between Sample and Population?

How many data points do I need to enter?

How does the keypad entry mode work?

What does the geometric mean tell me?

How do I read the frequency table?

What do skewness and kurtosis numbers mean in practice?

How do I change the number of decimal places in my results?

Which normality test should I use?

What does the p-value mean in hypothesis testing?

What is the difference between a one-tailed and two-tailed test?

When should I use Welch's t-test instead of a pooled t-test?

What is the difference between Pearson and Spearman correlation?

What does R-squared mean in regression?

When should I use logistic regression instead of linear regression?

How do I read the box plot?

What is the Q-Q plot used for?

Can I use this calculator for paired data?

What is the Mann-Whitney U-Test used for?

How does the Chi-Square Goodness-of-Fit test work?

What does the odds ratio mean in logistic regression?

Is my data saved or sent to a server?

Can I compare more than two groups at once?

What is the confidence interval telling me?

Related Math calculators

ANOVA Calculator

Average Calculator

Chi Square Calculator

Confidence Interval Calculator

Correlation Coefficient Calculator

Critical Value Calculator

Effect Size Calculator

EV Calculator

IQR Calculator

Linear Regression Calculator

Mean Median Mode Calculator

Median Calculator

Normal Distribution Calculator

Outlier Calculator

p Value Calculator

Percent Change Calculator

Percent Error Calculator

Percentage Calculator

Percentile Calculator

Range Calculator

Sample Size Calculator

Standard Deviation Calculator

t Test Calculator

Variance Calculator

Weighted Average Calculator

Z Score Calculator