be based on the real yield of Inflation-indexed bonds offered by some governments, including the United States, Canada, and the United Kingdom. The TIP$TER retirement calculator projects the retirement expenditures that a portfolio of inflation-linked bonds, coupled with other income sources like Social Security, would be able to sustain. Current real yields on United States Treasury Inflation Protected Securities (TIPS) are available at the US Treasury site. Current real yields on Canadian 'Real Return Bonds' are available at the Bank of Canada's site. As of December 2011, US Treasury inflation-linked bonds (TIPS) were yielding about 0.8% real per annum for the 30-year maturity and a noteworthy slightly negative real return for the 7-year maturity. Many individuals use "retirement calculators" on the Internet to determine the proportion of their pay they should be saving in a tax advantaged-plan (e.g., IRA or 401-K in the US, RRSP in Canada, personal pension in the UK, superannuation in Australia). After expenses and any taxes, a reasonable (though arguably pessimistic) long-term assumption for a safe real rate of return is zero. So in real terms, interest does not help the savings grow. Each year of work must pay its share of a year of retirement. For someone planning to work for 40 years and be retired for 20 years, each year of work pays for itself and for half a year of retirement. Hence, 33.33% of pay must be saved, and 66.67% can be spent when earned. After 40 years of saving 33.33% of pay, we have accumulated assets of 13.33 years of pay, as in the graph. In the graph to the right, the lines are straight, which is appropriate given the assumption of a zero real investment return. The graph above can be compared with those generated by many retirement calculators. However, most retirement calculators use nominal (not "real" dollars) and therefore require a projection of both the expected inflation rate and the expected nominal rate of return. One way to work around this limitation is to, for example, enter "0% return, 0% inflation" inputs into the calculator. The Bloomberg retirement calculator gives the flexibility to specify, for example, zero inflation and zero investment return and to reproduce the graph above. The MSN retirement calculator in 2011 has as the defaults a realistic 3% per annum inflation rate and optimistic 8% return assumptions; consistency with the December 2011 US nominal bond and inflation-protected