Financial Rules of Thumb oh Financial Rules of Thumb

  1. When estimating income, $1 an hour in wage is equivalent to $2000 per year in pre-tax earnings. The reverse is also true: $2000 per year in salary is equal to $1 an hour in hourly wage. (This rule works because the average worker spends roughly 2000 hours per year on the job.)
  2. How wealthy should you be? According to the authors of The Millionaire Next Door, the following “wealth formula” can tell you if you’re on target: Divide your age by ten, then multiply by your annual gross income. Your net worth should be equal to this number (less any inheritances).So, if you’re 40 and make $50,000 per year, your net worth should be $200,000. If you have less than half the expected amount, you’re an “under-accumulator of wealth”. If you have twice the target, you’re a “prodigious accumulator of wealth”. (Note that the authors are well aware that this formula doesn’t work well for young people; it’s meant to be used by folks nearing retirement age.)
  3. On average, each dollar an American spends represents about $2.50 of after-tax value in ten years or $10 in thirty years. (If you live outside the U.S., the consequences of spending that dollar are probably even greater.) This is due to two reasons: taxes and compounding. When you buy something, you spend after-tax dollars. On average, Americans have to earn $1.33 to have $1.00 left over.
  4. Inflation is the silent killer of wealth. In the U.S., inflation has averaged 3.18% over the past hundred years. A lot of folks figure a 3% inflation rate when making money calculations. I think it’s safer to assume 3.5% — or even 4% — average inflation in the future.
  5. Historically, U.S. stocks have earned long-term real returns (meaning inflation-adjusted returns) of about 7%. Bonds have long-term real returns of around 2.5%. Gold and real estate have long-term real returns of close to 1%.
  6. If you withdraw about four percent of your savings each year, your wealth snowball will maintain its value against inflation. During market downturns, you might have to withdraw as little as three percent. If times are flush, you might allow yourself five percent. But four percent is generally safe. (For more on safe withdrawal rates, check out this article from the Mad Fientist.)
  7. Based on the previous rule of thumb, there’s a quick way to check whether early retirement is within your reach. Multiply your current annual expenses by 25. If the result is less than your savings, you’ve achieved financial independence — you can retire early. If the product is greater than your savings, you still have work to do. (If you’re conservative or have low risk tolerance, multiply your annual expenses by 30. If you’re aggressive and/or willing to take on greater risk, multiple by 20.)
  8. Building on the above, Mr. Money Mustache’s shockingly simple math behind early retirementgives us a useful rule of thumb for determining how long you’ll need to save before you’re financially independent. Figure out your current saving rate (or profit margin, if you prefer). Subtract this number from 60. Roughly speaking — and assuming you’ve started from a zero net worth — that’s how long you’ll need to work before your nest egg is big enough to support you in retirement. (Note that this rule breaks down at saving rates over 40%. If you save a lot, subtract from 70.)
  9. Joe from Stacking Benjamins likes what he calls the “penny approximation”: Assuming a safe withdraw rate of roughly four percent, every $100 you save gives you one penny per day in perpetuity. Once you stack enough Benjamins you have enough pennies to sustain you forever. If you change your own brake pads and save $200, thats two cents a day for the rest of your life because you avoided paying a mechanic.