Select gender and age, select the event (or enter the distance) and enter your result, then press Age-grade to lookup the age-grading factors of the Masters Long Distance Running Council of USATF.
This calculator uses the most recent Road Event Age-grading factors (2020), which are maintained by Alan Jones.
Track and field and Walks versions are also available.
Also shown are the Open and age-graded standards. Your age-performance as a % of the Age std is calculated from these. This performance can be compared between different events.
Pressing Result will calculate your result for a given age-performance - e.g. use your age-performance in one event to predict a different event or the same event at a different age.
Times can be entered as hh:mm:ss[.dd] - if no colon is supplied, the time will be taken as seconds; only one colon will be interpreted as mm:ss.
Factors available as Excel file with macros.