Math & Statistics

What Is Margin of Error?

Margin of error is the amount by which a survey or poll result may differ from the true value in the whole population, at a stated confidence level, usually 95%. A result of 52% with a margin of error of ±3 points means the true value is likely between 49% and 55%.

Sample Size

For a percentage near 50% at 95% confidence, the margin of error is roughly 1 ÷ √(sample size): about ±3 points for 1,000 respondents.

What It Does Not Cover

It reflects random sampling error only, not biased questions or unrepresentative samples.

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% Percentage Calculator Three calculators in one: percentage of a number, percentage of total, and percentage change. Calculate → 📉 Standard Deviation Calculator Sample and population standard deviation and variance, with a step table. Calculate →

🔗 Related Terms

Confidence Interval Standard Error Sample vs. Population Percentage Point

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Last updated: September 29, 2026. This definition is for general educational purposes only. It is not financial, investment, tax, legal, or medical advice, and it does not recommend any product or course of action. For decisions about your own situation, consult a qualified professional.