T-Test Calculator - Calculator See


T-Test Calculator

Perform Student's t-test for single samples, independent two-samples, or paired samples to compare population means.

Calculator Inputs

Mean of sample 1.
Spread.
Observations in sample 1.
Mean of sample 2.
Spread.
Observations in sample 2.

Calculated Results

Calculated t-Statistic
t = 2.500 (p = 0.0223)
Degrees of Freedom (df) 18
Two-Tailed P-Value 0.0223
Statistical Significance Significant (p < 0.05)
Values calculate live as you adjust inputs.

About T-Test Calculator

Evaluates whether the difference between two sample means is statistically significant or attributable to sampling variation.

What is T-Test Calculator?

Evaluates whether the difference between two sample means is statistically significant or attributable to sampling variation.

How to Use This Calculator

  1. Enter mean, standard deviation, and sample size for both groups.
  2. View t-statistic, degrees of freedom, and p-value.

The Mathematical Formula & Variables

t = (Mean1 - Mean2) / sqrt(s1^2/n1 + s2^2/n2)

Step-by-Step Worked Example

Scenario: Sample 1 mean 105 (n=10) vs Sample 2 mean 95 (n=10).

  1. Mean difference = 10.
  2. Pooled variance standard error ≈ 4.0.
  3. t = 10 / 4.0 = 2.50 with df = 18.

Result: t = 2.500, p = 0.0223

Frequently Asked Questions

When should you use a t-test instead of a z-test?

Use a t-test when the population standard deviation is unknown and the sample size is relatively small (typically n < 30).