statistics probability

Sample Size Calculator for Surveys & Research

Statistical sampling tool based on Cochran's formula. Determines required respondents for statistical significance.

Input Parameters

Population Size (N)

Confidence Level

Accepted Margin of Error (e %)

Instant Calculation Result

Estimated Output

Active in Real-Time

Adjust values on the left to calculate live results.

Formula: Cochran's Formula: n = (Z² * p * (1-p)) / e². Finite adjustment: n_adj = n / (1 + (n-1)/N).

In-Depth Guide & Mathematical Methodology

👥 Sampling & Confidence Levels

95% Confidence (Z = 1.96): Standard benchmark in scientific and social research.

Margin of Error (e = 5%): Represents maximum expected error between sample estimate and true population value.

Frequently Asked Questions (FAQ)

What is the Sample Size Calculator for Surveys & Research and how does it work?

Statistical sampling tool based on Cochran's formula. Determines required respondents for statistical significance.

How do I use this Sample Size Calculator for Surveys & Research?

Enter Population Size ($N$) (use 100,000 for infinite population). Select Confidence Level (90%, 95%, or 99%). Enter tolerated Margin of Error ($e$ %). View Minimum Recommended Sample Size ($n$).

What mathematical formula is used in this calculation?

Cochran's Formula: n = (Z² * p * (1-p)) / e². Finite adjustment: n_adj = n / (1 + (n-1)/N).

Is the Sample Size Calculator for Surveys & Research on FindCalculator free to use?

Yes, all 330+ interactive tools on FindCalculator.online are 100% free, run directly in your browser without registration, and do not store your private calculation data.

More Free Calculators in STATISTICS

Weighted, Geometric & Harmonic Average Calculator

Compute Weighted Average ($w_i$), Geometric Mean ($\sqrt[n]{\prod x_i}$), and Harmonic Mean.

Confidence Interval Calculator for the Mean

Compute Confidence Interval ( $CI = \bar{x} \pm Z \frac{s}{\sqrt{n}}$ ) and Margin of Error ($ME$) for population mean.

Mean, Median, Mode & Range Calculator

Compute key measures of central tendency and dispersion: Arithmetic Mean ( $\bar{x}$ ), Median, Mode, and Range for a dataset.

P-Value & Statistical Significance Calculator

Evaluate P-Value ( $p$-value ) and Statistical Significance for hypothesis testing given a $Z$ score.

Permutations & Combinations Calculator (nPr & nCr)

Compute Combinations ( $nCr = \frac{n!}{r!(n-r)!}$ ) and Permutations ( $nPr = \frac{n!}{(n-r)!}$ ) for $n$ items chosen $r$ at a time.

Simple & Compound Event Probability Calculator

Compute Classical Probability ( $P(A) = \frac{\text{favorable}}{\text{total}}$ ), Complementary Event ( $P(A^c) = 1 - P(A)$ ), and Odds.