Survey Sample Size Calculator

What are you estimating? (count)

Choose 'A percentage' if you are estimating a share of people who answer a certain way, or 'An average' if you are estimating a quantity like spending, hours or a score.

Confidence level — any level; ninety-five percent is the usual choice

Enter the confidence level as a percentage between 50 and 99.99; ninety-five percent is the usual choice for most surveys.

Margin of error you can accept, in percentage points

Enter the margin of error in percentage points you can accept for a percentage estimate, between 0.01 and 50; a smaller number needs a larger sample.

Percentage you expect to find, if you have an idea (fifty is the safe choice)

Enter the percentage you expect to find, between 0.01 and 99.99; if you have no prior estimate, fifty is the safe choice because it needs the largest sample.

Population size — how many people the survey is about

Enter how many people the survey is about, between 1 and 100,000,000,000; this adjustment matters most when the population is small or medium sized.

Response rate you expect

Enter the response rate you expect as a percentage between 1 and 100; a lower response rate means more people must be invited to reach the same number of completed responses.

Results

Completed responses you need is 383. That requirement before rounding up is 382.68. People to select, before rounding up is 382.68. People to select or invite is 383.

Completed responses you need
That requirement before rounding up
People to select, before rounding up
People to select or invite