Sample Size Calculator for Survey Beginners
Determine exactly how many people you need to survey for accurate results. Simple, fast, and perfect for beginners.
If you don't know, leave this blank. It only matters for small populations.
Why Use Our Sample Size Calculator?
Beginner Friendly
No complex statistics jargon. Just enter your basic requirements and get the number you need.
Scientifically Accurate
Uses the standard Cochran's formula and finite population correction for precise results.
Save Resources
Don't over-survey. Find the exact number of responses needed to save time and money.
Survey Sampling Basics
When conducting a survey, you rarely need to ask everyone in a population to get a reliable answer. Instead, you survey a "sample" of the population.
Key Terms Explained
- Confidence Level: How sure you can be. 95% is the industry standard. It means if you repeated the survey 100 times, 95 times the results would be accurate.
- Margin of Error: Also called the confidence interval. If 50% of your sample says "Yes" with a 5% margin of error, the true number is between 45% and 55%.
- Population Size: The total number of people in the group you are studying. For large groups (like "all teens in the US"), you can leave this blank.
Frequently Asked Questions
What is a good sample size for a survey?
For most general surveys, a sample size of 385 is sufficient to get a 95% confidence level with a 5% margin of error for a large population. However, this depends on your specific accuracy needs.
What is margin of error?
The margin of error tells you how much you can expect your survey results to reflect the views of the overall population. A 5% margin of error means the true answer is likely within 5 percentage points of your survey result.
Why does sample size matter?
A correct sample size ensures your survey results are statistically significant and reliable. If your sample is too small, your results may not represent the population. If it's too large, you waste resources.