Calculating the age of the earth is not dependent upon evolution. Geologic time and astrological time are not dependent on evolution or even on biologic life forms.
http://pubs.usgs.gov/gip/geotime/age.html
http://biologos.org/questions/ages-of-the-earth-and-universe
I doubt you will find any reputable mathematician, one who also has a strong grasp of geology, astronomy and biology telling anyone that macro evolution would take trillions of years. And even if he did, if one does not believe that macro evolution exists or ever took place, then what difference would that have on the age of the Earth?
In other words lets say that I have a 5 quart pot of cold water and a 7000 BTU gas burner on which to heat the water to boiling. I bought the pot 10 years ago and have a receipt for it to prove it. I say it will take 10 minutes to bring the water to a boil but you say it will take 3 times that long. If it takes 10 minutes, does that change the age of the pot? Even if it does takes 3 times as long as I said, does that change the age of the pot?
No, long ages geology and astrology both contain one rather damning assumption - call uniformitarianism - the same rate of change under limited conditions then it must be the same for times and all other physical variations usually those outside of science ability to measure directly like high heat and pressure as found in the molten crusts and deeper geologic conditions.