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ISEVEN Function

The ISEVEN function in Excel is used to check whether a number is even. It returns TRUE when the number divides exactly by two and FALSE when it does not. Decimal values are truncated toward zero before the test, so ISEVEN reports on the integer part of the number rather than rejecting fractional input. This function is useful for alternating row logic, splitting records into two groups, and validating that a count or identifier has the expected parity.

Key Features of ISEVEN:

  • Returns TRUE when the number is even and FALSE when it is odd.
  • Truncates decimals toward zero before testing, so ISEVEN(2.5) returns TRUE because the integer part is 2.
  • Treats 0 as even, so ISEVEN(0) returns TRUE.
  • Handles negative numbers by parity of the truncated value — ISEVEN(-4) returns TRUE.
  • Is the exact complement of ISODD for every value both functions accept.

Syntax:

ISEVEN(number)
  • number: The value you want to test for evenness. Typically a cell reference, a literal number, or a formula result.

How ISEVEN Works:

  1. ISEVEN converts the supplied value to a number.
  2. The number is truncated toward zero, discarding any fractional part.
  3. If the truncated value divides exactly by two, ISEVEN returns TRUE; otherwise it returns FALSE.

Truncation happens before the parity test, not after, which is why ISEVEN(2.9) and ISEVEN(2) give the same answer.

Examples:

1. An Even Integer:

=ISEVEN(4)

Result: 

TRUE

2. An Odd Integer:

=ISEVEN(7)

Result: 

FALSE

3. Zero:

=ISEVEN(0)

Result: 

TRUE (zero divides exactly by two)

4. A Decimal Value:

=ISEVEN(2.5)

Result: 

TRUE (2.5 is truncated to 2 before the parity test)

5. A Negative Number:

=ISEVEN(-4)

Result: 

TRUE

6. A Small Negative Decimal:

=ISEVEN(-0.9)

Result: 

TRUE (truncation toward zero gives 0, which is even)

7. Banding Alternate Rows:

=IF(ISEVEN(ROW()), "Shaded", "Plain")

Result: 

Alternates between "Shaded" and "Plain" down the column

8. Splitting Records Into Two Groups:

=IF(ISEVEN(A1), "Group A", "Group B")

Result: 

Assigns each record to one of two groups based on the parity of its identifier

Notes:

  • ISEVEN truncates rather than rounds. ISEVEN(3.9) is FALSE because the integer part is 3, even though 3.9 rounds to 4.
  • ISEVEN is a scalar function. Unlike ISTEXT or ISBLANK, it evaluates a single value rather than mapping across a range.
  • A value that cannot be converted to a number produces an error rather than FALSE. Guard uncertain input with ISNUMBER first.
  • #N/A and infinite values are rejected as invalid numeric input.
  • ISEVEN is part of the IS family of information functions (ISBLANK, ISERR, ISERROR, ISEVEN, ISLOGICAL, ISNA, ISNONTEXT, ISNUMBER, ISODD, ISTEXT, etc.).

Applications:

  • Alternating Row Formatting: Combine with ROW() to band a table without a helper column.
  • Batch Assignment: Split invoices, orders, or users into two balanced groups by identifier parity.
  • Data Validation: Confirm that a quantity that must come in pairs really is even before processing.
  • Scheduling: Drive fortnightly or every-other-period logic from a week or period number.
  • Checksum Logic: Implement parity checks in identifier validation routines.
  • ISODD: Returns TRUE if the number is odd — the exact complement of ISEVEN.
  • ISNUMBER: Returns TRUE if the value is a number; useful as a guard before ISEVEN.
  • EVEN: Rounds a number up to the nearest even integer, rather than testing it.
  • MOD: Returns the remainder of a division — MOD(A1,2)=0 is the manual equivalent of ISEVEN(A1).
  • TYPE: Returns a numeric code indicating the data type of a value.
  • N: Converts a value to a number — logical TRUE becomes 1 and FALSE becomes 0.

Tip: ISEVEN truncates toward zero rather than rounding, which is easy to forget when the input is a calculated value rather than a whole number. If the fractional part is meaningful to your test, wrap the argument in ROUND or INT explicitly so the parity you get is the parity you meant.