Editing Retirement (section)

===Calculations using actual numbers===
Although the 4% initial portfolio [[withdrawal rate]] described above can be used as a rough gauge, it is often desirable to use a retirement planning tool that accepts detailed input and can render a result that has more precision. Some of these tools model only the retirement phase of the plan while others can model both the savings or accumulation phase as well as the retirement phase of the plan. For example, an analysis by ''[[Forbes]]'' reckoned that in 90% of historical markets, a 4% rate would have lasted for at least 30 years, while in 50% of the historical markets, a 4% rate would have been sustained for more than 40 years.<ref>{{cite web|url=https://www.forbes.com/sites/fidelity/2015/03/04/five-ways-to-protect-your-retirement-income/|archive-url=https://web.archive.org/web/20150306230311/http://www.forbes.com/sites/fidelity/2015/03/04/five-ways-to-protect-your-retirement-income/|url-status=dead|archive-date=6 March 2015|title=Five Ways To Protect Your Retirement Income|website=[[Forbes]]|date=4 March 2015|access-date=9 March 2015}}</ref>

The effects of making inflation-adjusted withdrawals from a given starting portfolio can be modeled with a downloadable spreadsheet<ref>http://retireearlyhomepage.com/re60.html downloadable spreadsheet</ref> that uses historical stock market data to estimate likely portfolio returns. Another approach is to employ a retirement calculator<ref>[http://firecalc.com FIRECalc: A different kind of retirement calculator<!-- Bot generated title -->].</ref> that also uses historical stock market modeling, but adds provisions for incorporating pensions, other retirement income, and changes in spending that may occur during the course of the retirement.<ref>{{cite web|url=https://www.nesteggly.com/retirement-calculator|title=The Ultimate Retirement Calculator}} retirement calculator that incorporates inflation, pensions and social security</ref>