taterules said:
The rule of thumb I've heard recently is that if you're retiring at 65, you'll want $25 in retirement money for every $1 you plan on taking out per year (this is already adjusting for inflation, I believe). Of course, getting a solid financial plan together with all your personal information, probably with a fee-based professional, is the best idea.
I rule of $25/$1 is pretty much the same as drawing down 4% of the balance each year (i.e. in both cases, your money is gone in 25 years). So that would mean that inflation has NOT been taken into account.
Here's how you can take inflation into account:
1. Determine how much income per year you want in today's dollars (that's taking your current income and multiplying it by that 70-80%).
2. Determine your annual inflation index. Do this by adding the rate of inflation to 1 (3% => 1.03, 4% => 1.04).
3. Multiply your desired income (from #1) by the inflation index (from #2). Repeat this for the number of years til retirement.
Example: $100,000 income, 75% desired at retirement, 3% inflation, 10 years til retirement.
$100,000 * 0.75 * 1.03 * 1.03 * 1.03 * 1.03 * 1.03 * 1.03 * 1.03 * 1.03 * 1.03 * 1.03
The result is the amount of income you'll need at a future date.
A short cut to determine '1.03 * 1.03 * 1.03 * 1.03 * 1.03 * 1.03 * 1.03 * 1.03 * 1.03 * 1.03' is to use the 'x^y' key found on some calculators (if you are running windows, you can find this key in the calculator program if you select "Scientific" from the 'View" menu). Key in '1.03' '^' '10' '='
For this example (3% for 10 years) the result of 1.03^10=1.3439.
So $100,000 * 0.75 = $75,000.
$75,000 * 1.3439 = $100,793.
So if you want a today's income of $75,000, in ten years you'll need an income of almost $101,000.
For easy access, here's a few of the multiplication factors assuming 3% inflation:
Years - Inflation Factor (assuming 3%)
1 - 1.0300
2 - 1.0609
3 - 1.0927
4 - 1.1255
5 - 1.1593
6 - 1.1941
7 - 1.2299
8 - 1.2668
9 - 1.3048
10 - 1.3439
11 - 1.3842
12 - 1.4258
13 - 1.4685
14 - 1.5126
15 - 1.5580
16 - 1.6047
17 - 1.6528
18 - 1.7024
19 - 1.7535
20 - 1.8061
21 - 1.8603
22 - 1.9161
23 - 1.9736
24 - 2.0328
25 - 2.0938
26 - 2.1566
27 - 2.2213
28 - 2.2879
29 - 2.3566
30 - 2.4273
31 - 2.5001
32 - 2.5751
33 - 2.6523
34 - 2.7319
35 - 2.8139
36 - 2.8983
37 - 2.9852
38 - 3.0748
39 - 3.1670
40 - 3.2620
You'll notice that after 24 years, you need twice as much money as today. At 38 years, you need three times as much money.