Re: Help with calculations
Get IRS Circular E, it has all the tables, percentages, exemptikons, calculations, etc. for federal withholding. Of course, some state & cities also have income taxes.
Note also that the tables and withholding rates change periodically.
Start googling.
I wrote one of these years ago in Lotus 1-2-3, that my firm's account used you our payroll. I had to maintain it and he got bent out of shape when I stopped maintaining it when I becase aware that he was using it for other clients.
There's lots of commerical programs and web sites that perform the calculations.