# The Formula You Are Using To Determine How Much To Save For Retirement Is Broken

If you are trying to figure out how much money you need to save for retirement, there’s an easy rule of thumb that you can use: simply multiply your expected annual expenses in retirement by twenty-five.

For example, if you expect to spend \$100,000 annually once you’re retired, you’ll want to have a \$2.5 million portfolio saved up. If you’d like to play around with the numbers to estimate your own retirement needs, you can use this simple retirement calculator.

This retirement savings rule of thumb is based on the 1998 landmark study conducted by Carl Hubbard, Philip Cooley and Daniel Walz, in their seminal study known as the Trinity Study. They built on the 1994 work of William Bengen, who originally coined the ‘4% Rule’.

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The Trinity Study evaluated safe retirement withdrawal rates, and found that 4% was sufficient for the majority of retirees. A safe withdrawal rate simply refers to the amount of money that can be taken out of an account and allow you to reasonably expect the portfolio to not fail, or run out of money. In this case, the 4% withdrawal rate refers to the amount of money that will be withdrawn from the balance of the retirement portfolio in the first year of retirement. In subsequent years, the balance withdrawn will simply be an inflation adjusted number based on the total dollar amount withdrawn the year prior.

The Trinity Study has become so well-known, that it has been adopted by hopeful retirees from all walks of life, including those hoping to retire early. The FIRE movement (Financial Independence, Retire Early) is a lifestyle movement with the goal of allowing individuals to retire as early and quickly as possible.

However, one detail that the movement is getting wrong and completely missing, is the fact that the Trinity Study’s 4% rule of thumb was based on a 30 year retirement period. This time horizon was determined to be on the conservative end of retirements by the authors of the study. If you work until you’re 65, having a 30 year retirement seems pretty reasonable. I don’t think many would argue that living until the age of 95 is a short life by any means.

The problem arises due to the FIRE movement seeking a much longer retirement period. If you retire at 45 years old, you may need a portfolio that will survive another 45 to 50 years in order to avoid running out of money. In this case, making a judgement error could end up meaning re-entering the workforce at an advanced age. For this reason, relying on a 4% withdrawal rate is an extremely risky decision if you plan to retire early.

This begs the question of what a more appropriate withdrawal rate is if you plan to retire early. The answer is that it depends. In general, the study found that as the balance between stocks and bonds shifts towards equities, a portfolio is more likely to withstand the test of time. So inherently, your risk tolerance will need to be factored into the equation. If you are comfortable with 75%+ of your portfolio being in stocks (and stomaching the increased risk), you might be safe with a 3% withdrawal rate. If you prefer less volatile investments, a lower rate is more conservative.

This is bad news for a lot of you hoping to retire early.

For one, it would mean having to save an additional \$833,000 if you hope to spend \$100,000 annually like in the example above. Unless you are an exceptionally high earner, it’ll likely mean having to work for several additional years or having to continue to earn additional income even after retirement.

With the buzz surrounding the gig economy and the seemingly endless ‘side-hustle’ opportunities available, this seems like a surmountable hurdle. The deficit in retirement savings required also highlights the impact of having to save for retirement as efficiently as possible.

This means fully taking advantage of your 401(k), IRA, and other tax-advantaged accounts. It also means evaluating whether it makes sense to refinance your student loans or not. Avoiding credit card interest fees and other forms of high interest debt are a must. In addition, maximizing your earning potential will also help safeguard your nest egg from market turbulence and economic uncertainty.

Just as important, you’ll also want to avoid making costly investment mistakes. One that comes to mind is erroneously viewing your vehicle as a sound investment. Another pitfall is picking individual stocks in lieu of index funds or ETFs. To set yourself up for success, minimizing fees and diversifying your investments is the name of the game.

Does all of this mean that the 4% rule is futile and should be completely ignored? Absolutely not. The authors of the Trinity Study ran simulations to find what the safe withdrawal rate would be for varying time horizons. But at the end of the day, they were just that: simulations. Even if you only had an expected 15 year retirement and used a conservative withdrawal rate, there is always the chance that your portfolio could fail. The same is true in the opposite direction: there’s always the chance that a 4% withdrawal could be sufficient for a 50 year retirement.

The question you have to answer is whether you are comfortable taking that risk. I know I’m not.

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Camilo Maldonado is Co-Founder of The Finance Twins, a personal finance site showing you how to budgetinvestbanksave & refinance your student loans. He also runs Contacts Compare.

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