WHAT YOU INPUT:
The five cells that you will want to tinker with are highlighted in green. Changing other cells will change a formula.
The five highlighted cells give the initial data for the following columns:
1. The year
You'll probably just want to insert the present year.
2. Chronological Age
This could be your present age or the age of anyone you're interested in calculating.
3 Days added to life span/year
Ray Kurzweil stated that in 2003 we were adding 120 days to human life expectancy every year. This is a number that's completely speculative and is fun to tinker with.
4. Annual % Improvement
Kurzweil also stated that in 10 years we would be adding more than a year every year to our life expectancy. Obviously this is a significant threshold - the end of senescence and the beginning of age reversal. For purposes of this spreadsheet we need a number for percentage increase in the number of days added to life expectancy.
To reach age reversal in 10 years from 120 present improvement, Kurzweil is contemplating about 8%. I lean toward a more conservative 2%. Again, this is a completely speculative number.
By the way, I don't think advances will be this smooth. I think improvements in life expectancy will occur in jumps.
5. Life expectancy
This is the present life expectancy of the person you're running. To find a present life expectancy value, I recommend this site:
http://moneycentral.msn.com/investor/calcs/n_expect/main.asp
WHAT THE SPREADSHEET RETURNS:
Continuing moving across the first row of the spreadsheet you'll find the "years left" column. This column simply subtracts current chronological age from life expectancy.
The "biological age next birthday" column is found by simply adding a year to the current chronological age and then subtracting the number of days added to the life span.
The "probability of death in the specified year" is based on information from the U.S. Department of Health and Human Services:
http://www.cdc.gov/nchs/data/series/sr_02/sr02_129.pdf
To make this data more manageable, I used ten year averages (5 year averages for the very young and very old). You can find this averaging on the "sheet 2" tab.
"Present chance of living through end of specified year" is just an inversion of the last column (1-probability of death in specified year).
The "J" column returns "probably dead" if the "present chance of living through end of specified year" falls below 50%.
The "K" column returns "aging reversed" when the "days added to life span/year" exceeds 365.