Units > To Insert Units
  
To Insert Units
1. Click where you want to insert units. It can be to the right of a term in an expression, inside a unit placeholder, or in a blank space of your worksheet. The cursor appears.
2. Type the name of a unit. You may have to insert a scaling operator to separate the name of the unit from the name of a variable.
Alternatively, on the Math tab, in the Units group, click Units. The units list opens displaying all the names of the built-in units. Click the unit to insert. The labeled unit appears after a scaling operator.
3. Repeat step 2 and multiply, divide, or raise units to a power until you obtain the desired units: