Compare calculators

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

Sample Size Calculator

Calculate the minimum number of respondents needed to estimate a population proportion within a given margin of error at a chosen confidence level — the standard formula behind almost every survey, poll, and quality audit. Includes the finite-population correction so you can plan surveys of small populations without over-sampling.

Population Size

Confidence Level

Margin of Error (%)

Fill in the required fields to see your result.

Probability

Hypothesis Testing Calculator

Run a one-sample t-test to decide whether a sample mean differs significantly from a hypothesised population mean. Returns 1 (reject the null hypothesis) or 0 (fail to reject) at your chosen confidence level using the one-sample t-statistic and a critical-value lookup.

Sample Mean

Population Mean (H₀)

Sample Standard Deviation

Sample Size

Test Type

Confidence Level

Fill in the required fields to see your result.

Key differences

	Sample Size Calculator	Hypothesis Testing Calculator
Category	Statistics	Probability
Inputs required	3	6
Result	Required Sample Size	Reject Null Hypothesis
What it does	Calculate the minimum number of respondents needed to estimate a population proportion within a given margin of error at a chosen confidence level — the standard formula behind almost every survey, poll, and quality audit. Includes the finite-population correction so you can plan surveys of small populations without over-sampling.	Run a one-sample t-test to decide whether a sample mean differs significantly from a hypothesised population mean. Returns 1 (reject the null hypothesis) or 0 (fail to reject) at your chosen confidence level using the one-sample t-statistic and a critical-value lookup.