The Excel TRUNC function truncates a number to a set number of digits by simply dropping the rest — it cuts toward zero without any rounding.
Syntax
| Argument | Description | |
|---|---|---|
number | Required | The number you want to truncate. |
num_digits | Optional | How many digits to keep. Defaults to 0 (drop all decimals). Negative values truncate left of the decimal. |
How to use it
TRUNC chops off digits beyond num_digits — no rounding, just truncation toward zero:
TRUNC and INT match for positive numbers, but differ for negatives: TRUNC cuts toward zero (-5.9 → -5), while INT rounds down (-5.9 → -6).
TRUNC keeps the sign-safe whole part. Because it always cuts toward zero, =A1-TRUNC(A1) returns the fractional part with the same sign as the original number — handy for splitting whole and fractional parts.
Try it: interactive demo
Pick a TRUNC example to see the formula and its result.
Practice workbook
Frequently asked questions
What's the difference between TRUNC and INT?
-5.9 → -5) while INT rounds down toward negative infinity (-5.9 → -6).Does TRUNC round?
=TRUNC(3.789, 1) is 3.7, not 3.8, because nothing is rounded.Is TRUNC the same as ROUNDDOWN?
num_digits is optional (defaults to 0), while ROUNDDOWN requires it.Can TRUNC keep decimal places?
=TRUNC(3.14159, 2) returns 3.14.Master functions like this in one day
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