The Rule of 72 is well known: Divide 72 by a rate of return to get the number of years for your money to double. Example: at 4.5% return it will take 72/4.5= 16 years to double your money
Here are a few more quick calculations:
Cost Before Taxes
Multiply an item’s cost by 1.4 to figure out what you need to earn before taxes to afford it
Example: A $250 Nintendo Wii will require 250*1.4= $350 in pre-tax earnings
Hourly Rate to Yearly Salary
Double your hourly rate and add three zeros to get approximate yearly salary
Example: at $20/hour, you make about 20*2 = 40 –> $40,000 per year
Yearly Salary to Hourly Rate
Opposite of above: Remove three zeros from your yearly salary and cut in half to get an approximate hourly rate
Example: at $60,000 per year you make about 60,000 –> 60/2 = $30/hour
Current Spending Versus Nest Egg Worth
Add a zero to the cost
Example: Using $2,000 for a new computer today would have been worth 2,000 –> $20,000 in a retirement account 30 years from now.
Calculations assume a 40 hour work week, 8% investment return, and 28% tax bracket.
If you enjoyed this post, subscribe to my feed via RSS or email.
You can support Richer by the Day by visiting our advertisers and sponsors. A thumbs up from any StumbleUpon users would also be greatly appreciated.
Related Posts
ToolsFinancial Rules of Thumb Stink
ING Your Number
Getting the Maximum Out of Your Company’s 401K Match (Updated)
Cadillac Ad Offers the Worst Financial Advice




