ERA
Level 2

Matching old W4 form allowances to new W4 form

I currently have 5 allowances allocated on my (old) W4 form. I need to change this to 4 allowances so more money is withheld for taxes. How do I reflect this change on the new W4 form? In other words, what's the formula that maps these two forms, so that the new W4 form equates to the same $ that corresponds to 4 allowances?