There are many benefits to trading up to a home with more square footage, especially for growing families. But with more house comes more cost, and, as a recent analysis by Zillow reveals, it can vary by location.

Trade-up homeowners can expect to spend an average $447 more each month if they move from a home with two bedrooms to one with three, according to Zillow’s Cost of Moving Up Analysis, or 50 percent more tacked on to a monthly mortgage payment.

“While deciding whether to move is a personal choice, understanding how certain characteristics like size, location, or number of beds and baths, can impact a home’s price can be hugely important when determining if a particular home is the right fit for you and your family,” says Dr. Svenja Gudell, Zillow’s chief economist. “Even though many families may be prepared to spend extra for a larger home, just how much more may come as a surprise, especially for those living in coastal markets.”

In several markets, trading up from two bedrooms to three adds less expense to a monthly mortgage payment than the average—in some cases, a lot less. In Cleveland, trading up from two bedrooms to three will cost a negligible $74 more each month, while trading up in Philadelphia will cost only $77 more. Trade-up homeowners in Indianapolis, Baltimore and Kansas City (Mo.) will pay below-average costs, as well: $103, $105, and $112, respectively.

Trading up from two bedrooms to three in high-priced markets, however, comes at a steeper cost: above average at $2,224 more each month in San Jose; $1,660 more in San Francisco; $1,033 more in Los Angeles-Long Beach-Anaheim; $928 more in San Diego.; and $601 more in Denver.