Formula Guide

The Excel INT Function
explained simply

INT rounds a number down to the nearest whole number — always toward negative infinity, unlike TRUNC.

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

What does INT do?

INT rounds a number down to the nearest whole number, dropping any decimal portion. For positive numbers this looks identical to ROUNDDOWN — the difference shows up with negatives.

INT always rounds toward negative infinity, so -4.3 becomes -5, not -4.

Syntax

=INT(number)
ArgumentDescription
number requiredThe number to round down.

Examples

Example 1
Round down a positive number
=INT(8.9)

Returns 8.

Example 2
Round down a negative number
=INT(-8.9)

Returns -9, not -8 — INT always moves toward negative infinity.

Example 3
Extract whole units from a measurement
=INT(17.6/4)

17.6 divided by 4 is 4.4 — INT gives you 4 whole groups.

Common mistakes

⚠️ Assuming INT and TRUNC always agree

They match for positive numbers but diverge for negative ones — INT(-8.9) is -9, TRUNC(-8.9) is -8.

FAQ

Is INT the same as ROUNDDOWN(number,0)?
For positive numbers yes. For negative numbers, ROUNDDOWN moves toward zero while INT moves toward negative infinity — they disagree.

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Related formulas

TRUNC ROUNDDOWN ROUNDUP