One-Sample T-Test Calculator
Perform one-sample t-tests to compare sample mean against population mean
About this calculator
The One-Sample T-Test Calculator performs statistical hypothesis testing to determine if a sample mean significantly differs from a known or hypothesized population mean. This test is essential when you have a small sample size (typically n<30) and unknown population standard deviation. It's widely used in research, quality control, and data analysis to make evidence-based decisions about whether observed differences are statistically significant or due to random variation.
How to use
Enter your sample data values or provide the sample mean, standard deviation, and sample size. Specify the hypothesized population mean you want to test against. Choose your significance level (typically 0.05) and select whether it's a one-tailed or two-tailed test. The calculator will compute the t-statistic, degrees of freedom, and p-value.
Frequently asked questions
When should I use a one-sample t-test instead of a z-test?
Use a one-sample t-test when your sample size is small (n<30) or when the population standard deviation is unknown, which is most real-world scenarios.
What does the p-value tell me in the results?
The p-value indicates the probability of obtaining your observed results if the null hypothesis were true. Values less than 0.05 typically indicate statistical significance.
What's the difference between one-tailed and two-tailed tests?
One-tailed tests check if the mean is significantly greater than or less than the hypothesized value. Two-tailed tests check if it's simply different in either direction.