Compare two independent proportions for A/B testing or comparing completion rates or conversion rates for small and large sample sizes.

Compute confidence intervals around continuous data using either raw or summary data.

Use this calculator to determine if there is a significant difference between 2 small sample completion rates.

Use this calculator to generate both a one-sample confidence interval and to test against a critera or benchmark.

Use this calculator to understand how sample size changes will affect the confidence interval around a completion rate.

Hover over the normal curve to display the area and z-score.To enter specific values use the Z-Score to Percentile Calculator or the Percentile to Z-Score Calculator.

Enter the area under the normal curve (a proportion between 0 & 1) and get the Z-critical value, one-sided or two-sided.

Enter a z-critical value and get the area under the normal curve (a percentage). Selecting two-sided provides the area above Z and below -Z.

This calculator produces an estimate of the number of users needed to discover the specified percent of total problems. It uses the Good-Turing and Normalization procedure.

This calculator takes raw task times, them using the Natural Logarithm and computes a confidence interval. The values are displayed in the dot-plots graphs.

Use this calculator to generate both a one-sample confidence interval and to test against a critera or benchmark.

Use this calculator to understand how sample size changes will affect the confidence interval around a completion rate.

This calculator produces an estimate of the number of users needed to discover the specified percent of total problems. It uses the Good-Turing and Normalization procedure.

Compare two independent proportions for A/B testing or comparing completion rates or conversion rates for small and large sample sizes.

Use this calculator to determine if there is a significant difference between 2 small sample completion rates.

Enter the area under the normal curve (a proportion between 0 & 1) and get the Z-critical value, one-sided or two-sided.

Enter a z-critical value and get the area under the normal curve (a percentage). Selecting two-sided provides the area above Z and below -Z.

Compute confidence intervals around continuous data using either raw or summary data.

Hover over the normal curve to display the area and z-score.To enter specific values use the Z-Score to Percentile Calculator or the Percentile to Z-Score Calculator.

This calculator takes raw task times, them using the Natural Logarithm and computes a confidence interval. The values are displayed in the dot-plots graphs.