How to Use ROUNDUP and ROUNDDOWN in Excel: Simple Guide
Use
ROUNDUP(number, num_digits) to always round a number up, and ROUNDDOWN(number, num_digits) to always round down. The num_digits controls how many decimal places to keep or which digit to round to.Syntax
ROUNDUP and ROUNDDOWN have the same syntax:
number: The number you want to round.num_digits: How many digits to round to. Positive for decimals, zero for whole numbers, negative for digits left of the decimal.
excel
ROUNDUP(number, num_digits) ROUNDDOWN(number, num_digits)
Example
This example shows how to round the number 3.14159 up and down to 2 decimal places.
excel
=ROUNDUP(3.14159, 2) =ROUNDDOWN(3.14159, 2)
Output
3.15
3.14
Common Pitfalls
People often confuse ROUNDUP and ROUNDDOWN with the regular ROUND function, which rounds normally (up or down based on value). Also, using a negative num_digits rounds digits left of the decimal, which can be confusing.
Example of mistake:
- Using
ROUNDUP(3.14159, -1)rounds up to 10, not 3.1.
Correct use:
ROUNDUP(3.14159, 1)rounds up to 3.2.
excel
=ROUNDUP(3.14159, -1) =ROUNDUP(3.14159, 1)
Output
10
3.2
Quick Reference
| Function | Purpose | Example | Result |
|---|---|---|---|
| ROUNDUP | Always rounds number up | =ROUNDUP(2.3, 0) | 3 |
| ROUNDDOWN | Always rounds number down | =ROUNDDOWN(2.7, 0) | 2 |
| ROUND | Rounds normally (up or down) | =ROUND(2.5, 0) | 3 |
Key Takeaways
Use ROUNDUP to always round numbers up, regardless of decimal value.
Use ROUNDDOWN to always round numbers down, ignoring decimal value.
The num_digits argument controls decimal places or digits left of decimal.
Negative num_digits rounds digits left of the decimal point.
Do not confuse ROUNDUP/ROUNDDOWN with the normal ROUND function.