# Calculation vs Estimation. What is the difference and when to use each of them?

Many times in books/articles I see terms "Calculation" and "Estimation". What is the difference between these two terms and when to use each of them?

You estimate the population mean from the sample.

You calculate the population mean from full enumeration.

Generally calculation is for a known quantity and an estimation had variance attached to it.

But to confuse things calculation is sometimes used just to describe manipulating numbers. E.g. I did a calculation of the s.d of the mean.

Calculation will result a Certain answer , but Estimation is a calculation which we are not certain about the answer and the answer is probability most time more than 90%.

We can calculate how many unemployment exist in percent. For example, 20% ( we are sure about this number as we divide number to the total.)

But we cannot calculate how many unemployment will be next year. We estimate it . It maybe be 30% (and we are not sure cause many thing may change during the time)