http://mapfight.appspot.com/
United States (9,833,000 km²) is 26.02 times as big as Japan (377,930 km²).
Alaska (US) (1,717,854 km²) is 4.55 times as big as Japan (377,930 km²).
But, Japan (377,930 km²) is 17.12 times as big as Israel (22,072 km²).
https://www.cia.gov/library/publications/the-world-factbook/geos/ja.html