Student’s T Distribution CDF Calculator with Graph
Enter a t‑value and degrees of freedom (ν) to compute the CDF. The graph below shows the CDF curve.
The CDF is computed using the incomplete beta function.
e.g., 1.5
e.g., 10
CDF at t = 1.5:
How It Works
The Student’s T CDF is computed using:
$$ F(t; \nu) = \begin{cases} 1 – \tfrac{1}{2} I_{\frac{\nu}{\nu+t^2}}\Bigl(\tfrac{\nu}{2},\tfrac{1}{2}\Bigr) & t \ge 0, \\ \tfrac{1}{2} I_{\frac{\nu}{\nu+t^2}}\Bigl(\tfrac{\nu}{2},\tfrac{1}{2}\Bigr) & t < 0, \end{cases} $$
The graph plots the CDF over a range of t‑values (from –5 to 5) and highlights the computed value.