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Both calculators run independently — change the inputs on either side to compare results.

Margin of Error Calculator

Find the margin of error for a survey proportion at a chosen confidence level. Tells you how far a poll result might be from the true population value.

Sample Size (people)

Sample Proportion (%)

Z-Score (1.96 = 95%)

Statistics

Standard Deviation Calculator

Compute the sample standard deviation directly from three summary statistics — sample size n, the sum of values Σx, and the sum of squared values Σx². This is the spread metric used in virtually every empirical study, quality-control chart, and risk model.

Sample Size

Sum of Values

Sum of Squares

Key differences

	Margin of Error Calculator	Standard Deviation Calculator
Category	Statistics	Statistics
Inputs required	3	3
Result	Margin of Error (%)	Standard Deviation
What it does	Find the margin of error for a survey proportion at a chosen confidence level. Tells you how far a poll result might be from the true population value.	Compute the sample standard deviation directly from three summary statistics — sample size n, the sum of values Σx, and the sum of squared values Σx². This is the spread metric used in virtually every empirical study, quality-control chart, and risk model.