
Sample Size Calculator Examples
Example 1
You are about to do the fourth cycle of an audit for compliance to a particular program.
From the previous three cycles, compliance rates have been around 75%, with the desired standard error around 1.6.
There are 100,000 businesses on the frame.
What sample size should you use?
Use...
Confidence Level = 95%
Population = 100,000
Proportion = 0.75
Standard Error = 0.016
Then press calculate
 Before Calculate
 After Calculation

Example 2A
You have an allocated budget of $10,000 to determine how satisfied your customers are. You have decided to run a survey. Your database shows that you have 38,000 customers. Last year's survey determined 40% of clients were satisfied.
From your budget you have determined that 5,000 businesses can be approached. Is this too many?
Use...
Confidence Level = 95%
Population = 38,000
Proportion  Let's say 40% again
Sample Size = 5,000
Then press calculate
The estimated Standard Error, in this example is more accurate than it needs to be and therefore we can decrease the sample size with limited impact on the overall accuracy.
In example 2B below, we reduce the sample size to 500.
 Before Calculate
 After Calculation

Example 2B
Using the same scenario, as in example 2A, but using a sample size of 500.
Use...
Confidence Level = 95%
Population = 38,000
Proportion  Let's say 40% again
Sample Size = 500
Then press calculate
Although the estimated standard error has increased it is sufficient for our survey objectives.
It is important to ensure the sample size is the minimum size that will achieve the desired accuracy.
The decreased sample size will reduce provider burden and survey costs.  Before Calculation
 After Calculation


