Student T Distribution Calculator
Evaluate lower, upper and two-sided Student t tail probabilities for an entered statistic and degrees of freedom.
YOUR CALCULATION
Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Evaluate the Student t tail with the entered degrees of freedom rather than substituting a normal approximation.
Upper tail=½ I[df/(df+t²)](df/2,1/2) for t≥0; use symmetry for t<0
Worked example
At t=0 every degree of freedom gives lower and upper probability 0.5 and two-sided tail probability 1.
Assumptions and input details
This evaluates a distribution only. A valid t statistic, sampling model and appropriate degrees of freedom must be supplied; no data analysis or test selection is inferred.
References: NIST: probability distributions
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
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