Margin of Error Calculator

Calculate the margin of error for surveys and statistical estimates

Sample Size:

Confidence Level (%):

Standard Deviation (use 0.5 for proportion):

Population Size (optional):

Results:

Margin of Error: ±9.80%

Sample Size: 100

Confidence Level: 95%

Z-Score: 1.96

Standard Deviation: 0.5

Interpretation: With 95% confidence, the true population parameter is within ±9.80% of the sample estimate.

About Margin of Error

The margin of error represents the range of uncertainty in a sample estimate. It tells you how much the sample result might differ from the true population value.

Formula: MOE = z × (σ/√n) × FPC

Where FPC is the finite population correction factor (if applicable).

Key Points:

Larger sample size reduces margin of error
Higher confidence level increases margin of error
For proportions (like surveys), use standard deviation = 0.5