# Sample size calculator

## Test calculation

Calculate the sample size to gain the required test power and draw a power analysis chart.

Use this test for one of the following tests:
One Sample Z-Test
One Sample T-Test
Two Sample Z-Test
Two Sample T-Test (Pooled variance)
Two Sample T-Test (Welch's) - only approximation

### Statistic Data

 digits: 1 2 3 4 5 6 7 6 9 10 example digits=2: (0.001234 => 0.0012) tails: two (Ho:μ=μ) left (Ho:μ≥μ) right (Ho:μ≤μ) distribution: Normal T sample: One sample Two samples α: significant level (0-1), maximum chance allowed rejecting H0 while H0 is correct (Type1 Error) power: required test power effect size (unstandardized): standardized effect size: The power is expected to identify the effect. If one exists, H0 will be rejected. effect size (standardized) - the change the test is expected to identify standardized effect size - the change divided by the standard deviation. examples: 0.2 - small effect, 0.5 - medium , 0.8 - large σ1: standard deviation σ2: standard deviation

validation message