the size of the general population - it can be known or unknown.

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Example of sample distribution by two parameters
How to determine sample size
Of course, the ideal sample size is all respondents who are part of the audience you are studying. However, surveying the entire population is very time-consuming and expensive.

In addition, according to the laws of statistics, the results of a survey of 1,500 people and 10,000 respondents will differ insignificantly - by only a few percent. So, there is no point in taking too large a sample - it is necessary to find the "golden mean" between the number of survey participants and its margin of error.

The margin of error of a study is the acceptable percentage of error in the results. For example, a survey showed that 50% of the audience knows your brand, the margin of error is 5%. This means that 50±5% of the general population are familiar with the company's products in real life, i.e. from 45% to 55%.

As a rule, studies are conducted with an error rate of 1 to 10%. The most popular error rate is 3% or 5%. The smaller it is, the higher the probability of obtaining reliable results.
Reliability (confidence level) is another important indicator used in calculating sample size. It refers to the proportion of the audience for whom the survey results will be correct.

The level of reliability is set within 80-99%. If it is below 80%, then this data cannot be trusted, because it is incorrect for a large part of the target audience.

Most often, reliability at the level of 95% is used. If the budget allows, then you can south africa phone number list specify 99% or 99.9%, but then the sample will be larger.
Thus, there are three main parameters that influence the sample size:

error level - from 1% to 10%;
reliability - from 80% to 99%;
The level of reliability and error of the final data is set by the company, based on the business objective and the budget size. The size of the general population is determined by marketers. If the exact value is unknown, it may not be specified in the calculations at all. In this case, the sample will be calculated "with a margin".

There are different ways to calculate the appropriate sample size for your study - you can do it yourself or use an online calculator. Let's look at them in more detail.

Method 1: Calculate manually
Here is a simplified formula that you can use to determine the sample size yourself. Simply substitute the coefficient that corresponds to the selected level of reliability into the numerator, and the desired error size into the denominator. This will give you the number of respondents you need to survey.