How Big Is 100 Acres?

An acre is equal to 43,560 square feet, so 100 acres equals 4,356,000 square feet. An acre is 1/640 of a square mile, so 100 acres also equals about 0.16 square miles. Because 1 acre equals about 4046.86 square meters, 100 acres equals 404686 square meters in the metric system.