Sample Size Calculator
Calculate sample size for surveys and research studies, or determine margin of error for existing data
Calculate sample size for surveys and research studies, or determine margin of error for existing data.
Find Out The Sample Size
This calculator computes the minimum number of necessary samples to meet the desired statistical constraints.
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Use 50% if not sure
Leave blank if unlimited population size
Find Out the Margin of Error
This calculator gives out the margin of error or confidence interval of observation or survey.
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Leave blank if unlimited population size
About Sample Size Calculator
Calculate the minimum sample size needed for statistical significance or determine the margin of error for your survey results.
Key Concepts
- • Sample Size: Observations needed
- • Margin of Error: Accuracy range
- • Confidence Level: Result reliability
Z-Scores
- • 90% confidence: Z = 1.645
- • 95% confidence: Z = 1.96
- • 99% confidence: Z = 2.576
Tips
- • Use 50% proportion when uncertain
- • Larger sample = smaller error