Deciding how much to give to charity can be as hard as deciding which charity to give it to.

Let’s say you’re an average middle-class American. Statistically speaking, you’re probably not saving enough for retirement. And maybe you’ve got kids and a mortgage and car payments and. ... Start adding up your bills, and you might start to think you shouldn’t be giving away a penny.

Then again, if you’re an average middle-class American, you probably enjoy a life that’s immensely more comfortable than millions of people in this country and billions of people worldwide. You have central heating, you can pour a glass of water right from your faucet, you have a house with a roof. Looking at it that way, maybe you should give ... well, a lot.

So which is it — yank the purse strings to Scrooge-like tightness, or renounce material wealth like someone entering a monastery?

One way to find a happy medium, recommended by Stacie Price, a financial adviser and a partner at Evercore Wealth Management in Minneapolis, is to think of your budget as a pie. One slice goes to retirement savings. One slice goes to fixed expenses: mortgage or rent, utilities and so on. One to paying off debt. One to taxes.

And one slice is discretionary spending: restaurant meals, new clothes, the latest smartphone upgrade. “The only piece you should be taking it from are these nonessential things,” Price said.

Take that slice, and cut off a piece of it for someone who needs, say, clean drinking water more than you need that new pair of really cool boots. In other words, consider giving up a few splurges on behalf of your seriously splurge-deprived fellow humans.

If you think in terms of helping someone live a better life, “then you’re going to feel good that you gave up the pair of boots,” Price said.

Katy Read