T-Test Calculator

Calculate the t-statistic, degrees of freedom, and approximate p-value for a one-sample t-test.

Inputs

Sample Mean (x̄)

Population Mean (μ)

Sample Standard Deviation (s)

Sample Size (n)

Tab to move between fields

Results

T-Statistic

1.83

P-Value (two-tailed, approx)

0.07

Degrees of Freedom29

Standard Error2.74

Significant at α=0.05 (1=Yes)0

95% Margin of Error (z-approx)5.37

How to Use This Calculator

Enter Sample Mean (x̄), Population Mean (μ), and Sample Standard Deviation (s).
Set Sample Size (n).
Review T-Statistic and P-Value (two-tailed, approx).
Use Degrees of Freedom and Standard Error to inform your decision.
Use the chart to visualize the results and explore different scenarios by adjusting inputs.

How the result changes with Sample Mean (x̄)

Sample Mean (x̄)	T-Statistic	P-Value (two-tailed, approx)
-800,000	-292,155.21	0
-300,000	-109,581.03	0
300,000	109,508	0
800,000	292,082.18	0

What each input means

Sample Mean (x̄): The mean of your sample data.
Population Mean (μ): The hypothesized population mean under the null hypothesis.
Sample Standard Deviation (s): The standard deviation of your sample data.
Sample Size (n): The number of observations in your sample. Must be at least 2.

How this is calculated

Worked example, using the default values

Identify Input Parameters
4 parameters
Sample Mean (x̄) = 105, Population Mean (μ) = 100, Sample Standard Deviation (s) = 15, Sample Size (n) = 30 = 4 input(s) provided
Calculate T-Statistic
T-Statistic
1.8257 = 1.8257
Calculate P-Value
P-Value
0.0726 = 0.0726
Calculate Degrees of Freedom
Degrees of Freedom = df
29 = 29
Calculate Standard Error
Standard Error
2.7386 = 2.7386

Engine last updated July 11, 2026. Checked against 2 independently-derived tests — how we verify calculators.

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