# Sample Size Calculator wth Proportion Percentage, formulas # Sample-Size Calculator

An online sample size calculator with and without finite population corrections.

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*Population Size (N) is a optional input. Detailed Answer

Sample Size Formula

n = z2 * p * (1 - p) / e2

Where,

z value (e.g. 1.96 for 95% confidence level)

p = proportion (as a decimal),

e = margin of error (%).

Sample Size (with finite Population Correction)

n = [z2 * p * (1 - p) / e2] / [1 + (z2 * p * (1 - p) / e2 * N)]

Where,

z value (e.g. 1.96 for 95% confidence level)

p = proportion (decimal),

N = population size,

e = margin of error.

Detailed Description:

Population Size - The total number of people whose opinion or behaviour your sample will represent.

Confidence Level (%) - The Probability that your sample accurately reflects the attitudes of your population.The industry standard is 95%.

Margin of Error (%) - The range (measured as a percentage) that your populations response may deviate from your samples.

## z value

Our calculator used the following z-score values.

Confidence Levelz-score
70%1.04
75%1.15
80%1.28
85%1.44
90%1.645
91%1.7
92%1.75
93%1.81
94%1.88
95%1.96
96%2.05
97%2.17
98%2.33
99%2.576
99.5%2.807
99.9%3.29
99.99%3.89 ##### How the sample size used in Survey?

Sample Size can be used in different areas in the world and some of them are

1/ Market research and development(R&D)

2/ Customer satisfaction surveys(CSR)

3/ Education surveys(ES)

4/ Employee and human resources surveys(HRS)

5/ Healthcare surveys(HCS)

6/ Casual surveys

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