Generate a truth table in excel


I have the need to make a formula that gives you the truth table for a variable number of columns

Examples

sample 4-bit truth table


Answers:


Replace the FirstCell with a static reference to the cell that contains the first 2^1 value e.g. $D$1 for a 4-bit table (16 values) and autofill to the rest of the grid (in the example A1:D16)

=IF(MOD(ROW()-ROW(FirstCell),POWER(2, ((COLUMN() - COLUMN(FirstCell)) * -1) + 1)) >= (POWER(2, ((COLUMN() - COLUMN(FirstCell)) * -1) + 1) / 2),1,0)

The logic behind this is:

If the current row modulus 2 power current column (* -1 as the first value is in the last column and + 1 because it starts from 0) is greater or equal to half of 2 power current column, put the value as 1, else put the value as 0.