An Excel formula is an expression that calculates the value of a cell. In other words, an Excel formula is a way of defining a specific calculation in a worksheet.

All formulas in Excel should begin with an Equal sign (=). For example, the formula to add 50 to the value in cell A1 is

=A1+50

This formula will always add **50** to the value in A1, even when there is a change in that cell.

Now, an example of an Excel formula that is used to find the product numbers in two different cells. The following formula will return the product of numbers in the cells D3 and E3

=D3*E3

You can also use **Plus **(+) or **Minus **(-) symbols to begin an Excel formula, but once you confirm the entry, Excel will add an equal sign to the beginning that expression.

### Formulas using Functions in Excel

Excel contains 450+ pre-defined formulas called **Functions**. You can use these functions in formulas, or even combine multiple functions in a single formula.

The following are two Excel formulas used to extract First and Last names from a Full name. You can see that different functions like **LEFT**, **RIGHT**, **SEARCH** and **LEN** functions used in these formulas.

=LEFT(B8,SEARCH(" ",B8))

=RIGHT(B8,LEN(B8)-SEARCH(" ",B8))

Another Excel formula that uses **CHOOSE** and **WEEKDAY** functions to return the day from a date.

=CHOOSE(WEEKDAY(F4),"Sun","Mon","Tue","Wed","Thu","Fri","Sat")

## Commonly Used Excel Formulas

Following are the examples of some commonly used Excel formulas

**Extract nth word from a sentence**

Find Rows containing Duplicate values

Find Cells containing Duplicate Values

Count a Specific Letter in a data range

Count a Specific word in a data range

Convert Positive values into Negative.