For many Americans, housing costs aren't just another expense -- they shape how the rest of the budget comes together.

Yet figuring out how much you can reasonably afford to spend on housing has become increasingly complicated in recent years, as shelter costs continue to rise.

If you earn $80,000 a year -- the median household income -- a decades-old rule of thumb suggests spending no more than 30% of your income on housing, or about $2,000 per month. But for many earners, that's far from realistic, especially in large cities where housing prices have surged the most.

Since August 2020, home prices have surged by 45% across the U.S., according to the most recent CoreLogic Case-Shiller national home price data. Meanwhile, the cost of renting a two-bedroom apartment has climbed 22% during the same period, per Redfin.

As a result, nearly a third of American households are now considered "cost burdened," meaning they spend more than 30% of their income on housing, according to the most recent U.S. Census data.

When it comes to how much of your income to put toward housing, "something in the range of 35% to 39%" might be a more realistic standard, says Emmanuel Eliason, a certified financial planner in Colorado. Even so, the ultimate goal should be to work toward the 30% rule of thumb over time, he adds.

Spending 50% or more of your income on housing should be avoided, if possible, says Eliason. Dedicating that much to housing puts "undue pressure" on your budget, limiting your ability to save for future goals or cover unexpected expenses.

It's also worth remembering that housing costs are largely fixed; it's not easy to shop around for a better deal and they rarely decrease over time. That's why it's important to leave room in your budget for flexibility.

Here's a look at the maximum amount you can put toward monthly housing costs without crossing various thresholds if you earn $80,000 a year: