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Statistics
Margin of Error Calculator
Calculate the margin of error for a survey or poll based on sample size, confidence level, and proportion.

Margin of Error Calculator

Calculate the margin of error for your survey or poll. Enter the sample size, observed proportion, and confidence level to determine how precise your results are.

The margin of error indicates the range within which the true population value likely falls.

Formula: MoE = z × √(p(1-p)/n)

Where:

  • z = z-score for confidence level
  • p = sample proportion
  • n = sample size

With Finite Population Correction: MoE = z × √(p(1-p)/n) × √((N-n)/(N-1))

A smaller margin of error means more precise results. To reduce it: increase sample size or lower confidence level.

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