Sample Size & Power Calculator (for Surveys & Experiments)

Plan your study with this free Sample Size & Power Calculator. It supports: survey proportions (margin of error + FPC), two-proportion A/B tests, one-mean, and two-means (independent) designs. Choose your goal (compute sample size or compute power) and get instant results — plus an optional power curve.

How to use

1. Select Problem (Survey Proportion, Two Proportions, One Mean, Two Means).
2. Select Goal: Sample Size or Power.
3. Fill in parameters (α, power, MDE/effect size, σ, p’s, etc.).
4. Click Calculate. Toggle the power curve if desired.

Examples

• Survey: 95% confidence, E=0.05, p unknown → p=0.5, n≈385; with N=50,000 → FPC n≈381.
• A/B (proportions): α=0.05 (two-tailed), power=0.8, p₁=0.10 vs p₂=0.12 → n/group ≈ 3,900.
• One mean: α=0.05 (two-tailed), power=0.8, σ=10, Δ=3 → n≈70.
• Two means: α=0.05 (two-tailed), power=0.8, σ₁=σ₂=10, Δ=3 → n/group ≈ 140.

Notes: Planning formulas use normal approximations (common in survey & experiment design). For small samples or strict accuracy use exact or t-based methods.

Probability Distribution Calculator (Normal, Binomial, Poisson, Uniform, Exponential, Geometric)

Are you struggling with probability distribution problems? This free online Probability Distribution Calculator helps you calculate probabilities, mean, variance, and cumulative distribution functions for popular distributions:

• Normal Distribution
• Binomial Distribution
• Poisson Distribution
• Uniform Distribution
• Exponential Distribution
• Geometric Distribution

It instantly generates probability values, expected values, and graphs so you can visualize the distribution easily.

How to Use

1. Select the distribution type (Normal, Binomial, Poisson, etc.).
2. Enter the required parameters (e.g., n & p for Binomial, λ for Poisson, μ & σ for Normal).
3. Enter the value of X you want to calculate probability for.
4. Click Calculate to get PDF, CDF, and statistics.

Tip: Graphs are automatically drawn to help understand the distribution visually.

Why This Tool?

As a statistician and economist, I know probability distributions form the backbone of statistical analysis. This tool is designed for:

• 🎓 Students – checking homework & exams.
• 📊 Teachers – explaining probability concepts visually.
• 🏦 Economists & Bankers – risk modeling and forecasting.
• 📈 Researchers – analyzing event probabilities and expected outcomes.

Try it below and save hours of manual calculation!

Probability Distribution Calculator (Normal, Binomial, Poisson, Uniform, Exponential, Geometric)

Hypothesis Testing Tool (Z-test, T-test, Chi-square, ANOVA)

Do you need a quick and reliable way to test hypotheses in statistics? This free Hypothesis Testing Calculator helps students, teachers, economists, statisticians, and researchers perform:

• Z-test (one-sample & two-sample)
• T-test (one-sample, paired, independent)
• Chi-square test (goodness-of-fit & independence)
• ANOVA (one-way analysis of variance)

It generates step-by-step results including test statistics, degrees of freedom, p-value, and decision rule instantly.

Why This Tool?

As a statistician and economist, I know how tedious hypothesis testing can be without software. This online tool saves time and reduces error by instantly providing test results with interpretations. It’s especially useful for:

• 🎓 Students – quick homework and exam preparation.
• 📊 Teachers – explaining statistical tests in class.
• 📈 Researchers – analyzing experimental or survey data.
• 🏦 Professionals – making data-driven business decisions.

Try it now and share how it helps you in the comments!

Hypothesis Testing Tool (Z-test, T-test, Chi-square, ANOVA)

Use this free online Hypothesis Testing Tool to compute test statistics, degrees of freedom, and p-values with clear “Reject/Fail to reject” decisions. Supports: Z-test (one-sample mean, σ known), T-test (one-sample, two-sample Welch, paired), Chi-square (goodness-of-fit, independence), and one-way ANOVA.

How to use

1. Pick a test from the dropdown.
2. Enter data (raw lists or summary where required).
3. Choose the alternative (two-tailed / left / right) where applicable and set α.
4. Click Calculate to see results and interpretation.

Hypothesis Testing Tool (Z-test, T-test, Chi-square, ANOVA)

Examples

• Z-test (one-sample): Raw data 12, 15, 14, 16, 13; μ₀=14; σ=2.
• T-test (two-sample Welch): X: 10,12,9,11; Y: 13,14,12,15; Δ=0.
• Chi-square GOF: Observed 18,22,20,15,25; Expected blank (equal expected).
• Chi-square independence:
  10,20,30
6,14,20
• ANOVA:
  12,13,11
15,14,16,17
10,9,11,8

Correlation Coefficient Calculator (Pearson’s r, Spearman’s rho)

Do you need to quickly find the strength of relationship between two variables? This free Correlation Coefficient Calculator instantly computes Pearson’s r and Spearman’s rho with detailed steps and scatterplot visualization.

• Pearson’s r: Measures linear correlation between two sets of data.
• Spearman’s rho: Measures rank correlation (non-parametric).

How to Use

1. Enter two sets of values (X and Y) separated by commas or spaces.
2. Click Calculate to get Pearson’s r, Spearman’s rho, and graph.
3. Scatterplot with regression line is displayed for visualization.
4. Use Clear to reset and enter new data.

Why Use This Tool?

As an economist and statistician, I know the importance of quickly testing relationships between variables. This tool is especially useful for:

• 🎓 Students – verifying homework results.
• 📊 Teachers – showing real-time correlation in class.
• 📈 Researchers – analyzing surveys or experimental data.
• 🏦 Economists – checking financial or banking datasets.

Try it now and let me know in the comments how it helps you!

Correlation Coefficient Calculator (Pearson’s r, Spearman’s rho)

Simple Linear Regression Calculator (Free Online Tool with Graph)

Do you want to quickly calculate the linear regression equation, see the slope and intercept, and visualize your data with a scatter plot and regression line? This free online calculator makes it easy!

It is designed for students, teachers, economists, bankers, researchers, and data analysts who need a fast way to perform regression analysis without installing software.

What This Tool Does

• Computes the regression line: Y = b₀ + b₁·X
• Calculates slope (b₁) and intercept (b₀)
• Displays correlation coefficient (r) and R² (coefficient of determination)
• Plots a scatter diagram with the fitted regression line
• Works directly in your browser — no downloads, no Excel required!

How to Use

1. Enter your data pairs in the input box, one X, Y pair per line.
2. Click Calculate Regression.
3. The tool will instantly show the regression equation, correlation, R², and draw the graph.
4. Use Clear to reset and start again.

Example Input

Try pasting this sample dataset into the box:

1, 2
2, 3
3, 5
4, 4
5, 6

Expected output: a line close to Y = 1.3 + 0.9·X with a strong positive correlation.

Simple Linear Regression Calculator (Free Online Tool with Graph)

Why Use This Tool?

Linear regression is one of the most widely used methods in statistics, economics, and business research. It helps us understand the relationship between two variables, make forecasts, and test hypotheses. This tool is especially useful for:

• 🎓 Students learning regression analysis
• 📊 Teachers demonstrating concepts in class
• 🏦 Bankers & Economists analyzing financial data
• 📈 Researchers working with paired datasets

Descriptive Statistics Calculator (Mean, Median, Mode, Variance & Standard Deviation)

Do you need quick and reliable descriptive statistics without doing long manual calculations? This free online calculator helps students, teachers, economists, statisticians, and researchers calculate mean, median, mode, variance, and standard deviation for three types of data:

• Raw / Individual Data (simple list of numbers)
• Discrete Frequency Data (value with frequency)
• Continuous Grouped Data (class intervals with frequency)

It also generates frequency tables and working tables automatically, so you can check step-by-step results.

How to Use

1. Select your data type: Raw, Discrete, or Grouped.
2. Paste your data in the input box. You can copy-paste directly from Excel or Google Sheets.
3. Click Calculate to see results.
4. Use the Clear button to reset.

Tip: For grouped data, you can specify class width and choose inclusive/exclusive intervals.

Why This Tool?

As a statistician and economist, I know how time-consuming it can be to calculate basic descriptive statistics by hand, especially when dealing with large data sets. This tool saves time and reduces error by instantly computing results and displaying tables. It’s especially useful for:

• 🎓 Students – for quick homework or research checks.
• 📊 Teachers – to demonstrate statistics concepts in class.
• 🏦 Bankers & Economists – analyzing surveys, customer data, or loan distributions.
• 📈 Researchers – working with frequency tables and grouped data.

Try it out, and let me know in the comments how it helps you!

Descriptive Statistics Calculator (Mean, Median, Mode, Variance & Standard Deviation)for Individual and Grouped Data