Lump Sum Tax Calculator . In the context of pensions, the former is sometimes called the commuted value, which is the present value of a future series of cash flows required to fulfill a pension obligation. It is clear that the winner cannot simply receive the total advertised amount of the powerball jackpot immediately. Lump Sum Calculator AIRINC Workforce Globalization from www.air-inc.com We're open from 9am to 6pm, monday to friday. For example, if you have a pension of £25,200 and a standard lump sum of £75,600, the lump sum could be maximised as follows: A = p (1 + r/n) ^ nt.