Based in part on the tax brackets shown here: http://www.moneychimp.com/features/tax_brackets.htm http://www.moneychimp.com/features/tax_brackets.htm and severa

Based in part on the tax brackets shown here: http://www.moneychimp.com/features/tax_brackets.htm http://www.moneychimp.com/features/tax_brackets.htm and several years of adjusting my estimated taxes in order to get as close to a zero-balance as possible when I do my taxes in April.