Formula Guide

The Excel TRUNC Function
explained simply

TRUNC simply chops off the decimal portion of a number, with no rounding logic at all.

ExcelPro · 3 min read · Updated June 2026
Contents
  1. What does TRUNC do?
  2. Syntax
  3. 3 examples
  4. FAQ

What does TRUNC do?

TRUNC removes the decimal portion of a number, truncating toward zero, with no rounding involved — 8.9 simply becomes 8, no matter how close 8.9 is to 9.

It can optionally keep a specified number of decimal places instead of cutting to a whole number.

Syntax

=TRUNC(number, [num_digits])
ArgumentDescription
number requiredThe number to truncate.
num_digits optionalHow many decimal places to keep. Defaults to 0 (whole number).

Examples

Example 1
Truncate to a whole number
=TRUNC(8.9)

Returns 8 — simply cut, not rounded.

Example 2
Truncate a negative number
=TRUNC(-8.9)

Returns -8 — moves toward zero, unlike INT which would return -9.

Example 3
Keep 2 decimal places
=TRUNC(19.5678,2)

Returns 19.56, cutting off everything after the 2nd decimal.

Common mistakes

⚠️ Expecting TRUNC to round

It never rounds — it always just cuts off digits, even if the dropped portion was 0.999.

FAQ

When should I use TRUNC instead of ROUNDDOWN?
For whole numbers they behave the same. TRUNC reads slightly clearer when the intent is purely "cut off the decimals," not "round toward zero."

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Related formulas

INT ROUNDDOWN ROUND