Math & Trig

INT Function in Excel

Rounds a number down to the nearest integer.

Syntax

  • =INT(number)

Arguments

  • number (required): The number to round down

Examples

  • =INT(8.9) - Round down positive - Result: 8
  • =INT(-8.9) - Round down negative - Result: -9

Excel INT function documentation

  • INT rounds a number down to the nearest integer toward negative infinity.
  • Syntax: =INT(number). Not the same as rounding — INT(-3.2) returns -4.
  • Use for whole units, age from dates, stripping time from datetimes, and binning.
  • Related: [TRUNC](/functions/trunc/), [ROUND](/functions/round/), [MOD](/functions/mod/).

INT syntax and negative numbers

  • number (required): any numeric value or cell reference.
  • INT always rounds down — for positive numbers this matches removing decimals.
  • For negatives, INT moves away from zero — use [TRUNC](/functions/trunc/) to truncate toward zero.
  • INT(NOW()) returns today's date serial without time portion.

Step-by-step: remove time from datetime column

  • Step 1 — Datetimes in column A.
  • Step 2 — Date only: =INT(A2) in column B.
  • Step 3 — Format B as Date.
  • Step 4 — Copy values if you need to replace originals.
  • Step 5 — Alternative: =A2-INT(A2) returns time-only fraction.

INT vs TRUNC vs ROUNDDOWN

  • INT — floor toward -∞; best for date stripping on positive datetimes.
  • TRUNC — chop decimals toward zero; -3.2 → -3.
  • ROUNDDOWN — similar to TRUNC for most positive business math.
  • Category: [Math & Trig functions](/categories/math-trig/).

Worked examples to copy

  • Whole dollars: =INT(price).
  • Date from NOW: =INT(NOW()).
  • Complete weeks: =INT(days/7).
  • Extract time: =A2-INT(A2) formatted as time.

People also ask

  • INT vs ROUND down? — INT(-2.1) is -3; ROUNDDOWN(-2.1,0) is -2.
  • INT on dates? — Removes time; format cell as date.
  • INT #VALUE!? — Argument is text — use VALUE or fix source.
  • INT in age formulas? — Often paired with DATEDIF or YEARFRAC workflows.

Common errors

  • Rounds toward negative infinity, not toward zero

Use cases

  • Extract whole numbers
  • Age calculations
  • Integer division

Frequently asked questions

  • What's the difference between INT and TRUNC? For positive numbers, they're identical. For negative: INT(-8.9)=-9 (rounds toward negative infinity), TRUNC(-8.9)=-8 (removes decimals toward zero). Use TRUNC when you want to simply remove decimals regardless of sign.
  • How do I extract the decimal part of a number? Subtract INT from the original: =A1-INT(A1). For 8.75, this returns 0.75. For negative numbers, use =A1-TRUNC(A1) to get the decimal portion correctly.
  • How do I calculate age from birthdate? Use =INT((TODAY()-BirthDate)/365.25) for approximate age, or =DATEDIF(BirthDate, TODAY(), "Y") for exact years. INT is useful when dividing date differences.

Editorial review

  • Reviewed by Excel.Directory Editorial Team. Updated May 2026.

When to use INT

  • Extract whole numbers — common Math & Trig scenario for INT.
  • Age calculations — common Math & Trig scenario for INT.
  • Integer division — common Math & Trig scenario for INT.

INT in the Math & Trig category

  • Browse all Math & Trig functions at /categories/math-trig/ for related formulas.
  • INT syntax: =INT(number)
  • number (required): The number to round down
  • Confirm INT arguments match the syntax shown above before filling down.
  • Lock table and range references with $ when copying formulas across rows or sheets.

Formula checklist before you copy down

  • Confirm INT arguments match the syntax shown above before filling down.
  • Lock table and range references with $ when copying formulas across rows or sheets.
  • If results look wrong, check for text stored as numbers and invisible spaces with TRIM.
  • Spot-check three known input rows manually against expected output.

Related Excel functions

  • TRUNC (/functions/trunc/): Truncates a number to an integer by removing the decimal part.
  • ROUND (/functions/round/): Rounds a number to a specified number of digits.
  • FLOOR (/functions/floor/): Rounds a number down to the nearest multiple of significance.

Errors to watch for

  • Rounds toward negative infinity, not toward zero — review causes on linked error pages in the directory.

Copy-paste audit workflow

  • Enter INT on three test rows with known expected output documented on a QA tab.
  • Fill down only after absolute references are locked on lookup tables and rate tables.
  • Compare against manual calculation or a calculator for financial and statistical functions.
  • Search this directory for comparison guides when choosing between similar functions in the same category.

INT worked examples to copy

  • =INT(8.9) — Round down positive. Expected result: 8.
  • =INT(-8.9) — Round down negative. Expected result: -9.

INT reference summary for crawlers and offline review

  • INT belongs to the Math & Trig category in Excel. Rounds a number down to the nearest integer.
  • Full syntax: =INT(number). Open /functions/int/ for parameters, FAQs, and related pages.
  • Common mistakes: Rounds toward negative infinity, not toward zero
  • Pair this function with comparison guides when another Excel formula might fit the same task better.
  • Review fix-excel-formula-errors when unexpected errors appear after upgrading Excel or sharing across locales.