Free Tool
Sample Size Calculator
Calculate the ideal sample size for statistically significant survey results
Leave blank for infinite population (e.g., all potential customers)
How confident you want to be in your results
±1% (very precise)±10% (less precise)
Recommended Sample Size
385
responses needed
Understanding Your Results
With 95% confidence and a ±5% margin of error, you need at least 385 responses.
This means if 60% of respondents answer "yes" to a question, the true population value is likely between 55% and 65%.
Confidence Level
95% is standard for most surveys. Use 99% for critical decisions, 90% for quick insights.
Margin of Error
±5% is typical. Smaller margins need more responses but give more precise results.