How many people do you need to talk to to get a margin of error you are comfortable with? Consult our handy calculator and find out!

Listed below are few terms you will need to understand before using the sample size calculator:

Confidence Level: The percentage value that tells how confident a researcher can be about being correct. A 95% confidence level is a generally acceptable level of confidence and is most typically used and accepted within the research industry. Which means that if a study were conducted 100 times, answers would be within the margin of error 95 out of 100 times.

Margin of Error / Confidence Interval: Assumes that you have a random sample. The margin of error for a typical survey is +/- 5%. This means that results may vary as much as five percent in either direction. The margin of error for sub-samples (i.e. men versus women), is based on the number in that sub-sample.

Population Size: The population size is the universe from which you are taking your sample. If the population size is very large or unknown, leave this field blank.

DIRECTIONS:

• Choose a confidence level
• Enter an acceptable margin of error (between .1 and 50 - leave off % sign)
• Enter population (if known)
  Click on "calculate"
• This calculator requires Internet Explorer 3.0 or later or Netscape 3.0 or later or a compatible browser. Leave the population box blank, if the population is very large or unknown.

CAUTION: Sampling error is only one source of bias. Contact us to discuss other possible sources of bias (i.e. question bias).

(This sample size calculator was created by Creative Research Systems.)

The margin of error for a poorly designed survey: +/- 100%

* Based on a 95% level of confidence; assumes a random sample and worst-case (50/50) response.  If this does not make sense, it's time to call Riley Research.