Not all New York City views are created equal.

Direct Central Park views may be the most valuable amenity in Manhattan real estate, but in a market filled with soaring new developments — some of which wind up blocking the views of other buildings — even a partial glimpse of a river, park or the city skyline can also command a hefty premium.

To get a sense of how much people are willing to pay for the city’s most sought-after views, Jonathan Miller, the president of the appraisal firm Miller Samuel, looked at several buildings that have stunning vistas and compared the sale prices of apartments with similar layouts in each building — those with views and those without.

New Yorkers, he discovered, are generally willing to pay 10 to 25 percent more for an apartment that allows them to wander over to the window and take in the sights — whether that’s a boat moving up the river or the rolling lawns of Central Park.

Mr. Miller calculated a rough percentage of an apartment’s value that could be attributed solely to the view by winnowing out the other surcharges that might affect a property’s value, like a floor-level premium, which Mr. Miller said ran “about 1 percent for every floor you go up.” (In other words, all other things being equal, apartments along the same line typically increase in value at about 1 percent per floor.)