Calculating After-Tax Social Security Benefits By Kerry Pechter Thu, Dec 15, 2016 SHARE ON: TwitterFacebookLinkedIn A handy crib sheet recently published by Vanguard shows the formulae for calculating the portion of an individual's or couple's Social Security benefits that will be subject to ordinary income tax. Already a subscriber? Log in here This article is FREE for you... Create a free account to access this article and get more Retirement Income Journal information sent to you by newsletter. Email Password Or, subscribe now for unlimited access and a free book sent to you! By submitting your email address you agree for Retirement Income Journal to send you communication by email