While the specific answer varies from person to person, there are certain rules of thumb that can be useful across the board. So certified financial planner Mark Baird created a percentage guideline that breaks down how much you should spend in various categories, from savings to entertainment, depending on your household income.
"All of these ranges are guidelines, not strict rules," he writes in his book, "Rules to Riches." "But if you do adhere to them, you'll be in a much better financial position than you would otherwise. You will be mindful of what you spend, and that's half the battle."