What ROUND does
ROUND returns a number rounded to the number of digits you specify. It is useful for pricing, reporting, and any worksheet where visible precision should match the stored result.
Practical examples
Round to one decimal place
=ROUND(2.15, 1)
This returns 2.2.
Round to the nearest hundred
=ROUND(1548,-2)
This returns 1500 because a negative num_digits rounds to the left of the decimal point.
Common mistakes and notes
Formatting is not the same as rounding
Changing decimal display with cell formatting does not change the underlying stored value. ROUND changes the value itself.
Negative num_digits rounds to tens, hundreds, and beyond
Use -1 for tens, -2 for hundreds, and so on. That is useful in reporting but easy to overlook.
ROUND is different from TRUNC
ROUND adjusts values based on standard rounding rules, while TRUNC simply removes digits without rounding.