To find the standard deviation in Excel, use the built-in functions depending on whether your data is a sample or an entire population:

• For a sample standard deviation, use the formula:
  =STDEV.S(range)
  where "range" is the cells containing your data.

• For a population standard deviation, use:
  =STDEV.P(range)

Steps:

1. Enter your data into a column or row of cells.
2. Select an empty cell for the result.
3. Type the formula with your data range, for example, =STDEV.S(A1:A10) for sample data.
4. Press Enter to get the standard deviation result.

These formulas ignore text and logical values unless you use their variants (like STDEVA or STDEVPA) which include logical values and text as numbers. This method helps efficiently calculate the variability or spread of data in Excel.