CalculatorExpert.online
Sample Size Calculator
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Find how many responses you need for a statistically valid survey.
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| Unadjusted Sample Size | 385 |
| Final Sample Size (rounded up) | 385 |
How Sample Size Is Calculated
Sample size determines how many responses you'd need to be confident that your survey results reflect the whole population within your chosen margin of error. A higher confidence level or a tighter margin of error both increase the sample size needed.
n = ZĀ² Ć p Ć (1 ā p)EĀ²
Z = z-score for your confidence level, p = expected proportion, E = margin of error (decimal)
Finite Population Correction
If you know the total size of the population you're surveying (and it's relatively small), the calculator applies a correction that reduces the required sample size, since a larger share of a small population needs to be sampled to reach the same confidence.