Central Park is 2.5 times larger than Hyde Park, London.
Area: 3 km2 calculated
Central Park is an urban park in the New York City borough of Manhattan. It was initially opened in 1857, on 778 acres of city-owned land. In 1858, Frederick Law Olmsted and Calvert Vaux won a design competition to improve and expand the park with a plan they titled the Greensward Plan. Wikipedia
Area: 1 km2 calculated
Hyde Park is one of the largest parks in London, and one of the Royal Parks of London, famous for its Speakers' Corner. The park was the site of the Great Exhibition of 1851, for which the Crystal Palace was designed by Joseph Paxton. Wikipedia