NEW YORK (MainStreet) — Low mortgage rates and an improving job picture will prompt many renters to switch to homeownership in 2015, and here are three cities that market watcher sees as this year's best choices for first-time homebuyers.

"If your goal is to slow down, buy a home and stay there for a while, these are metro areas where places are still affordable," says Zillow economist Skylar Olsen, who compiled the firm's picks.

Zillow analyzed America's 50 most-populous metro areas to see which offer first-time buyers the best combination of affordability, a good supply of entry-level homes and rising median incomes.

Olsen says the winning cities are places where property prices either didn't go crazy during the recent housing boom, or did do so but later collapsed and haven't completely recovered.

Read More: 5 U.S. Markets That Are Already Back in Housing Bubbles

Of course, that means San Francisco and other cities with booming economies but soaring home prices didn't make the cut.

Olsen says those markets attract lots of young workers who'd love to buy their first homes, but can rarely afford to do so.

"If you ask Millennials which metros they feel confident they can become homeowners in, it's not San Francisco or New York," she says.

Read on to check out cities that Zillow believes offer 2015's first-time homebuyers the best market fundamentals.

The firm selected winners by looking primarily at how much median money households headed by a 23- to 34-year-old earn in each city and what share of gross monthly income young locals need to pay for entry-level homes. (The study defined "entry level" as properties priced in the bottom third of each metro area's October 2014 Zillow listings.)

Monthly payment figures assume buyers purchase places using 5% down payments, private mortgage insurance and 30-year fixed-rate mortgages at prevailing interest rates. All household-income numbers are as of 2014's third quarter and refer to families headed by 23- to 34-year-olds, while Zillow omitted metro areas that didn't have at least 5% annual increases in the number of available entry-level homes.

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Third-best market for first-time buyers: Chicago
Chicago is at least America's Second City when it comes to entry-level housing, offering the second-largest supply of starter homes of any city that Zillow analyzed.

Sellers have some 11,200 entry-level properties listed for sale, up 6.5% over the past year and trailing only New York's roughly 27,600 lower-priced listings.

The Windy City's first-time buyers can also expect to spend a mere 16.2% of monthly income on mortgage bills, while young workers' median household incomes have risen a solid 14.3% over the past five years.

"Chicago [offers first-time buyers] good inventory and good income growth and is still very affordable," Olsen says.

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Second-best market for first-time buyers: Atlanta
Scarlett O'Hara had to fight to keep her family's Atlanta-area home in Gone With The Wind, but the city's first-time buyers won't have the same problem today.

That's because the typical Atlanta entry-level buyer needs just 15.2% of monthly income to cover a mortgage. Zillow also found that young Atlanta workers have seen their median incomes rise a respectable 9.5% since 2009. 

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Add in the fact that Georgia's most-populous city has some 5,800 starter homes for sale -- a 19.5% increase over the past year -- and first-time buyers should find plenty of properties that they can afford.

Olsen says Atlanta has lots of modest-priced homes because property values tanked during the recent housing bust and have yet to fully rebound. "Home-value appreciation is strong in Atlanta, but still has a long way to go," she says.

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Best market for first-time buyers: Pittsburgh
Entry-level homes are a real steal in the Steel City.

First-time Pittsburgh buyers can expect to pay just 11.7% of median household income on their mortgages -- the lowest level of any metro area Zillow evaluated.

"Pittsburgh is extremely affordable," Olsen says.

The typical young Pittsburgh worker has also seen household income grow by an impressive 14.1% in the past five years, while the supply of entry-level homes has shot up 8% to roughly 3,300.

— By Jerry Kronenberg for MainStreet