How to use the P-value Calculator
Estimate p-value from z statistic with the P-value Calculator. It includes Two-sided P-value, Left-tailed P-value, Right-tailed P-value, Area from center to Z, Central probability, Probability between bounds workflows, so choose the one that matches the values you actually know. Use it to check the arithmetic while keeping the displayed method and entered values with your work.
Step by step
- For the P-value example, select Two-sided P-value and enter z statistic. Keep each value in the unit displayed beside its field.
- Review the selected P-value workflow and inputs, then read p-value in the result panel.
- Change one P-value assumption at a time to compare scenarios. Use Reset to restore this tool's worked example values.
How the calculation works
Converts between Z statistics and left-tail, right-tail, center, bounded, or two-sided standard-normal probabilities.
Worked example
To reproduce the P-value worked example, reset the calculator. Select the Two-sided P-value workflow. Use z statistic 1.96. The result is p-value of 0.04999565. Two-sided P-value: Converts between Z statistics and left-tail, right-tail, center, bounded, or two-sided standard-normal probabilities. Review the displayed units before comparing the result.
Understanding the result
The P-value reports p-value. Use it to check the arithmetic while keeping the displayed method and entered values with your work. The result depends on the entered values, selected mode, and displayed mathematical assumptions.
How to check the answer
Check the P-value answer by substituting p-value back into the stated relationship. Test a simple value such as zero, one, or an equal pair, then confirm that sign, scale, units, and rounding match Converts between Z statistics and left-tail, right-tail, center, bounded, or two-sided standard-normal probabilities.
Common questions
What does the P-value calculate?
Estimate p-value from z statistic with the P-value Calculator.
Which inputs does the P-value example use?
The worked example uses z statistic in the Two-sided P-value workflow. Other workflows can show different fields. Keep the chosen workflow and units with the result when comparing calculations.
Is the P-value result exact?
The result depends on the entered values, selected mode, and displayed mathematical assumptions. Recheck z statistic and use p-value only for a decision where that level of precision is appropriate.