The most typical old question that scientist struggle with is the exact age of the earth. Accepted earth’s age is about 4.54 billion years (plus or minus about 1%) which derives from several lines of evidence with many involved assumptions. Furthermore this age could not be computed directly and solely from the earth and its determinant properties without contemplate suppositions. Also no scientific method can prove earth’s actual age and the exact accretion time of earth as yet. In this paper exact age and accretion time of the earth are determined by a new basis parameter in universe that’s called strength limit number of earth and by other substantial factors. Results represented that present exact overall age of the earth is 4.7303652362904 billion years and age of the earth since earth’s initial complete formation (old age of the earth) is 4.55017504989450 17745329167415032 billion years. Therewith the exact accretion time of earth is 180.1901863 958982254670832584968 million years. Also complete formation and accretion time of the oldest known solid constituents in meteorites according to present exact age of the earth is 163.365236 2904 million years. Finally, strength limit factor of earth and distance that light travel in one year prove that the earth is created in 6 cycles. The exact age of the earth performs main fundamental impressment role in new scientific discoveries (such as biological and particles discoveries).