Output:

1. Navigate to Setup > Customization > Layouts and Fields.
   
2. Under Layouts, click on the layout template that you need to add a formula field to.
   
3. Select the module you want to customize and click on the specific layout template.
4. In the Add Field, click and drag the Formula field to the desired position in the layout.
   
5. Fill in the Basic Information:
   
1. Provide a Label for the formula field.
   
2. Choose the appropriate return type based on your calculation:
   
1. Boolean: Check box on True/False
   
2. Decimal: Numbers with decimal points
   
3. Currency: Monetary values
   
4. String: Text-based values
   
5. Date: Calendar date
   
6. DateTime: Date with time
   
3. Start writing your expression directly in the Expression Editor.
   
4. You can insert field names and operators from the available options instead of writing the entire expression manually.
   
5. The Field Expression box will display all fields from the selected layout for easy reference.
   
6. Use Operators:
   
1. + (Add)
   
2. - (Subtract)
   
3. * (Multiply)
   
4. / (Divide)
   
5. % (Remainder)
   
6. < (Less than)
   
7. > (Greater than)
   
8. ^ (Power)
   
9. . (Dot)
   
7. Click Check Syntax to verify if the formula is valid and error-free.
   
6. Once validated, click Add to save the formula field to the layout.
   

1. Boolean: A Boolean formula returns either TRUE or FALSE.
   
2. Decimal: The output of the expression and the formula field will return as a numeric value that can include decimals as 94.3.
   
3. Currency: Returns a value with a currency symbol, typically representing monetary values like $444.
   
4. String: Returns text values. Example: 'Hello' concatenates the string "Hello".
   
5. Date: Returns a date value (without time). Example: TODAY() returns the current date as 13.02.2025.
   
6. DateTime: Returns both date and time values. Example: NOW()rreturns the current date and time as 21/12/2005 06:30 AM.
   

1. Number Functions
   
1. Abs: Absolute value of the number.
   
2. Ceil: Smallest integer ≥ the number.
   
3. Floor: Largest integer ≤ the number.
   
4. Naturallog: Natural logarithm.
   
5. Base10log: Base 10 logarithm.
   
6. Max: Maximum value from a list.
   
7. Min: Minimum value from a list.
   
8. Sqrt: Square root of the number.
   
2. Text Functions
   
1. Len: Character count.
   
2. Equals: True if strings match.
   
3. EqualsIgnoreCase: True if strings match (case-insensitive).
   
4. IsEmpty: True if string is empty.
   
5. Find: Position of a letter.
   
6. Concat: Combine strings.
   
7. Contains: True if substring found.
   
8. Startswith: True if string starts with substring.
   
9. Endswith: True if string ends with substring.
   
10. Lower: Convert to lowercase.
    
11. Upper: Convert to uppercase.
    
12. Trim: Remove spaces from ends.
    
13. Substring: Extract part of a string.
    
14. Replace: Replace occurrences of a string.
    
15. ReplaceAll: Replace pattern matches.
    
3. Date & Time Functions
   
1. Dayofmonth: Day of the month.
   
2. Hour: Hour (24-hour format).
   
3. Minute: Minute of the time.
   
4. Month: Month of the date.
   
5. Year: Year of the date.
   
6. Yr: Last two digits of the year.
   
7. Weekday: Day of the week (1=Sunday).
   
8. Newdatetime: Create date with time in GMT.
   
9. Newdate: Create a date.
   
10. Adddate: Add time (ISO8061 format).
    
11. Subdate: Subtract time (ISO8061 format).
    
12. Now: Current date and time.
    
13. Datecomp: Time difference in minutes.
    
14. Instant: Current time in ISO format.
    
4. Logical Functions
   
1. If: Conditional value.
   
2. And: True if all conditions are true.
   
3. Or: True if any condition is true.
   
4. Not: Invert a boolean value.
   
5. Conversion Functions
   
1. Tonumber: Convert string to number.
   
2. Tostring: Convert any value to string.