The lunch savings calculator at soundmoney.publicradio.org lets you calculate what you save by bringing a lunch instead of eating out. You can adjust the average cost of going out for lunch, the cost of your brown-bag lunch and the frequency you eat out.
For example:
Cost of going out for lunch
$7
Cost of a brown-bag lunch
$3
Two-year savings from eating a bag lunch 20 times a month, at a 5 percent rate of return
$2,021
