Calculate Your Margin of Error & Sample Size
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What is a margin of error?
Surveying is an excellent tool to measure attitudes, opinions, and perspectives — but it’s important to consider whether your survey sample will accurately reflect the views from the overall population. To ensure that your sample size is large enough to be representative of the overall population, you’ll want to calculate your margin of error (also called a confidence interval). The margin of error will tell you how closely your survey sample reflects the overall population.
A margin of error represents a range of values below and above the actual results from a survey.
How to interpret your margin of error
The smaller your margin of error, the more confident you can be that your survey results are representative. The larger your margin of error, the farther your results can stray from the perspective of the overall population. For example, if 75% of respondents answer "yes" to a question and our margin of error is 5%, then between 70% and 80% of the overall population also believe that the answer is "yes".
Most researchers who want statistically significant results look for a margin of error to be 5% or lower. Feel free to play around with the calculator above to determine what sample size provides you with the margin of error that best fits the needs for your unique project.