Summary

BITAND compares two integers at the bit level and keeps only the bits that are 1 in both values. If a bit is missing from either side, it becomes 0 in the result.

This makes BITAND very useful for masks and flag checks. Instead of reading every bit manually, you can test whether a specific bit is on by ANDing the value with a mask and looking at the result.

Syntax

=BITAND(number1, number2)

number1 and number2 are the integers you want to compare.

Excel compares the two numbers bit by bit and keeps only the positions where both values contain a 1. Even though the logic happens in binary, the returned result is shown as a normal decimal number.

Arguments

• number1 - [required] The first non-negative integer.
• number2 - [required] The second non-negative integer.

Both arguments must be whole numbers greater than or equal to 0. In practice, these are usually decimal values that happen to represent bit patterns. If an argument is negative, too large, or not numeric, Excel returns an error instead of trying to guess what you meant.

BITAND vs similar functions

BITAND is for checking overlap between bit patterns, not for adding or toggling them:

Using BITAND

The most common pattern is using BITAND with a mask. If you want to know whether a specific bit is on, use the bit's value as the second argument. For example, if the mask is 8, then BITAND(value, 8) returns 8 when that bit is on and 0 when it is off.

This is also useful when a single integer stores several flags at once. Instead of breaking the number apart first, you can test one flag at a time with the matching mask. That keeps the formulas short and makes permission-style values much easier to read.

Excel's bitwise functions work with non-negative integers and support values up to 2^48 - 1. If the inputs go outside that limit, Excel returns #NUM!.

Example 1 - Compare 13 and 9

This keeps only the bits that both numbers share.

=BITAND(13, 9) // Returns 9

Example 2 - Check whether bit 8 is set

If the result equals the mask, that bit is on.

=BITAND(12, 8) // Returns 8

Example 3 - Test one permission bit

This pulls the execute bit out of a combined permission value.

=BITAND(7, 1) // Returns 1

Example 4 - Keep only one high bit

This is the same mask idea with a larger value.

=BITAND(1024, 1024) // Returns 1024

Quick recap

• Keeps shared bits: BITAND returns only the bits that are on in both inputs.
• Great for masks: It is one of the easiest ways to test whether a flag is set.
• Returns a number: The result is a decimal value, not TRUE or FALSE.
• Use powers of two as masks: Values like 1, 2, 4, and 8 target individual bits.
• Works only with non-negative integers: Excel returns #NUM! for values outside the supported range.