Margin Of Error Calculator
Estimate normal-theory margin of error for a mean or survey proportion.
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What Is the Margin Of Error Calculator?
This calculator estimates two-sided sampling margins for a numeric mean or proportion at common confidence levels.
How It Works
Choose mean or proportion, enter the appropriate spread or expected share and sample size, then select confidence.
When to Use It
Use it for early survey and study planning under a simple-random-sample assumption.
Frequently Asked Questions
- Does It Include Survey Bias?
- No. Coverage, nonresponse, weighting and measurement errors are outside this formula.
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