Do you want to buy your own home? If so, how much do you have saved toward a down payment? If you're a Millennial, somewhere between your mid-20s and late 30s, the answers to these questions are probably: yes, yes, and nothing or next to nothing. 

That's the dispiriting finding of a study published last month by Apartment List, which asked 6,400 Millennial renters about their home-buying plans, and applied their knowledge of the marketplace and some financial math to determine how easy or difficult it would be for those Millennials to purchase a home in the foreseeable future.

Here's what they found: 

1. Even though most Millennials want to buy a home, fewer than 5 percent can do so now.

Of the nearly 9 in 10 respondents who say they want to buy a home, only 4.9 percent thought they'd be able to do so within the next year. Just over a third said they would have to wait five years, or more.

2. Most have little or nothing saved for a down payment and it will take 20 years until they have enough.

Of those who want to purchase a home, 72 percent said they couldn't afford it, with 62 percent saying they specifically lacked a down payment, typically calculated at 20 percent of a home's purchase price. About half ot the Millennials in the survey said they had zero savings for a down payment. Only 11 percent said they had at least $10,000 saved, even though that would only be enough to purchase a $50,000 home.

How long will it take most Millennials to be able to buy a home? Apartment List did the math, comparing Millennial savings rates with real estate prices. They calculate that it would take two thirds of Millennials at least 20 years to save enough for a mid-priced condo in their market.

3. Student debt is keeping Millennials from buying homes.

If you're Millennial age or younger and you've been to college, you probably know just how big a burden student debt can be. Apartment List estimates that 23 percent of college graduates can save enough in the next five years to put a down payment on a home, while less than half that many graduates with student debt will be able to do so. Those who skip college altogether are even worse off. Only 6 percent will be able to afford a down payment in the next five years, according to Apartment List.

4. Down payments are the biggest problem.

Only 29 percent of the Millennials who can't afford to buy say they'd have trouble making their monthly mortgage payments. This makes perfect sense, because market economics tend to keep rents and mortgage payments fairly well aligned. (For example, my husband and I bought a house two years ago and our mortgage payment is within $35 of the rent we were paying beforehand.) It's usually the lack of money for a down payment that's preventing Millennials from becoming homeowners.

And so, as with many Millennial problems, tech startups may offer the solution. For example Loftium helps provide a down payment to home buyers willing to rent out part of their homes with Airbnb and pay Loftium a cut of what they earn. Others have looked to crowd-funding to solicit donations from family and friends. Will solutions like these be enough to make the difference? For the sake of the real estate industry, and the Millennials themselves, we'd better hope so. Otherwise there will be millions of people stuck as renters for decades longer than they want to be.