There are many variations to bingo, so the answer to this question will depend on the version you are playing. For example, American-style bingo usually has 25 squares while UK-style bingo has 36 squares.
Assuming you are playing American-style bingo, you will need to find the number of squares in a row and column. To do this, take the number of squares in a row and add 1 to it (for a total of 26).
Then take the number of squares in a column and add 1 to it (for a total of 27). This will give you the total number of squares needed for American-style bingo.
If you are playing UK-style bingo, you will need to find the number of squares in a column and row. To do this, take the number of squares in a row and subtract 1 from it (for a total of 25).
Then take the number of squares in a column and add 1 to it (for a total of 26). This will give you the total number of squares needed for UK-style bingo.