ROUNDDOWN function

The ROUNDDOWN function in Excel rounds a number down, toward zero, to a specified number of digits. Unlike ROUND, it always truncates the number without considering the value of the digits being removed.

Syntax

=ROUNDDOWN(number, num_digits)

Parameters

1. number (required): The number you want to round down.
2. num_digits (required): The number of digits to round to:
   • A positive value (n) rounds to n decimal places.
   • 0 rounds to the nearest whole number.
   • A negative value rounds to the left of the decimal point.

Examples

1. Round down 123.456 to 2 decimal places:

   =ROUNDDOWN(123.456, 2)
   

   Result: 123.45

2. Round down 123.456 to the nearest whole number:

   =ROUNDDOWN(123.456, 0)
   

   Result: 123

3. Round down 123.456 to the nearest tens place:

   =ROUNDDOWN(123.456, -1)
   

   Result: 120

4. Round down a number in cell A1 to 3 decimal places:

   =ROUNDDOWN(A1, 3)
   

Notes

• Behavior: The function always rounds down, no matter the value of the digits being removed (even if they are 5 or greater).
• If num_digits is:
  • Greater than 0, it rounds down to the specified number of decimal places.
  • 0, it rounds down to the nearest integer.
  • Less than 0, it rounds down to the left of the decimal point.

Related Functions

• ROUND: Rounds numbers up or down based on standard rounding rules.
• ROUNDUP: Always rounds numbers up, away from zero.
• TRUNC: Truncates a number to an integer by removing the fractional part without rounding.
• MROUND: Rounds to the nearest multiple of a specified number.

The ROUNDDOWN function is particularly useful when you need precise control over rounding behavior, ensuring results are consistently lower.