One Sample T-Test Calculator
Test a sample mean against a known or hypothesised value.
Enter your values
ⓘ Live results
Results
- t statistic
- 1.3403
- p-value (two-tailed)
- 0.2287
- Verdict
- Not significant at the 5% level
- Sample mean
- 5.1429
- Standard error
- 0.1066
- 95% CI for the mean
- 4.891 to 5.394
- Degrees of freedom
- 6
Quick answer
t = (sample mean − hypothesised mean) ÷ (s ÷ √n) with n − 1 degrees of freedom; a small p-value says the sample mean is unlikely under the null.
t = (x̄ − μ₀) ÷ (s ÷ √n)
How to use the One Sample T-Test Calculator
- 1Paste your sample values separated by commas.
- 2Enter the mean you are testing against.
- 3Read the p-value and check whether the confidence interval contains μ₀.
Worked example
Using the values the calculator loads with:
Inputs
- Sample values5.1, 4.8, 5.6, 5.2, 4.9, 5.4, 5.0
- Hypothesised mean μ₀5
Results
- t statistic1.3403
- p-value (two-tailed)0.2287
- VerdictNot significant at the 5% level
- Sample mean5.1429
- Standard error0.1066
- 95% CI for the mean4.891 to 5.394
- Degrees of freedom6
Frequently asked questions
What does the confidence interval add?
If it excludes your hypothesised mean, the two-tailed test is significant at that level — and the interval also shows the size of the difference.
Do I need normally distributed data?
For n above about 30 the test is robust. For small samples badly skewed data, use a sign test or Wilcoxon instead.
About this calculator
- Built and reviewed by James Whitfield · How we build and test calculators
- Report an error
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.