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ROUNDDOWN Function

Excel 2007+

Summary

The Excel ROUNDDOWN function rounds a number down to a specified number of digits, always toward zero. Unlike the standard ROUND function, ROUNDDOWN never rounds up, making it perfect for conservative estimates, flooring calculations, and precise financial truncations.

Syntax

ROUNDDOWN(number, num_digits)

Parameters

Parameter	Type	Required	Description
number	`Number`	Yes	The value you want to round down toward zero
num_digits	`Number`	Yes	Precision level: positive for decimal places, 0 for whole numbers, negative for tens/hundreds/etc.

Using the ROUNDDOWN Function

ROUNDDOWN is invaluable for scenarios requiring downward-only rounding, such as calculating maximum capacities, conservative projections, or truncating decimals without rounding up. It provides precise control over rounding direction across various precision levels.

Common ROUNDDOWN Examples

Basic Integer Rounding

=ROUNDDOWN(3.2, 0)

Rounds 3.2 down to the nearest whole number (3). Useful for counting units.

Decimal Precision Control

=ROUNDDOWN(3.14159, 3)

Rounds pi to 3 decimal places (3.141). Perfect for scientific calculations.

Negative Number Handling

=ROUNDDOWN(-3.14159, 1)

Rounds negative values down toward zero (-3.1). Consistent behavior.

Left-of-Decimal Rounding

=ROUNDDOWN(31415.92654, -2)

Rounds to nearest hundred (31400). Great for large financial summaries.

Frequently Asked Questions

ROUNDDOWN always rounds toward zero (down for positive, up for negative toward zero), while ROUND follows standard banker's rounding rules.

Yes, negative values round to the left of the decimal (tens, hundreds, etc.).

Absolutely - it can reference cells, ranges, or complex formulas as the number argument.

Common Errors and Solutions

#VALUE! Error

Cause: Non-numeric value in number argument

Solution: Ensure number parameter contains valid numeric data

Unexpected results with negatives

Cause: Misunderstanding 'down toward zero' behavior

Solution: Remember: -3.7 becomes -3.7 (closer to zero)

Notes

Always rounds toward zero regardless of number sign
Use 0 for integer flooring
Negative num_digits affects whole number places
Faster than INT for decimal rounding control

Compatibility

Available in: Excel 2007, Excel 2010, Excel 2013, Excel 2016, Excel 2019, Excel 2021, Microsoft 365

Not available in:

Content last reviewed: December 9, 2025
Update frequency: As needed
Excel versions tested: Excel 2007+