How many years old is the earth?

4.5 billion is the accepted answer Civilization has nothing to do with the age of the earth

Earth has been around for about 4 to 4.6 billion years, this is when the sun was formed and therefore created our planet

The Earth is around 4.5 billion years old. Scientists know this because of Radiometric dating, go here: http://en.wikipedia.org/wiki/Age_of_the_Earth Civilizations don't even matter. The Earth has been here longer than anything that has ever been on it (obviously), especially humans. http://en.wikipedia.org/wiki/Geologic_time_scale

4.55 billion years old.:))))

Learn about earth.Answer is 5. 1.Farley rigid solid inner core of 1250 km radius. 2.The outer liquid core of 2200 km thick. 3. The lower mantle of 2900 km thick. 4. The top most outer layers consist of Asthenosphere, lithosphere of 20 to 100km & crust of 30 km thick under the continents & only about even 5 km thick under the deep ocean, 5. It is about 4.75 Billion years old. 6. Life of our earth is another 4.75 billion years. 7. Mean distance to Sun 14,95,03,923 km. 8. Mean distance to moon 3,81577.5 km, 9. Equatorial diameter 12,756.8 km, 10. Mass ( In metric ton ) 5,974 X 10 ^18, 11. Period of revolution 365 days 5 hours 48 minute & 46 seconds, 12. Total area 51,00,66,000 Sq km, 13. Water area 29.1 %, 14. Land area 70.9 %, 15. Volume 10,83,230 X 10 ^ 6 Cubic k/m