Claim more than 1 when single

[CoachDavis1]

How is it possible to claim more than 1 when filing as single?

I get confused on this because only understand that I can only claim 0 or 1 as a single person. What allows a single person to claim more than and what des that mean when I claim 2 or 3 because I see this was suggested to me with the calculator. Please clarify what the number means as I increase it.

[kcumberland]

The number of allowances for you would depend on your individual situation. However, IRS removed the withholding allowances a few years ago.  The change streamlined the W4 allowing for an improved method of withholding taxes from your wages.   

TurboTax’s W4 Calculator will provide the corresponding line number with the amount to report based on the information entered.   If you want your federal withholding to be more accurate, gather your paycheck stub(s) and complete a new Form W4.  You can make changes after the adjustments take effect. 

https://turbotax.intuit.com/tax-tools/calculators/w4/