Take your one mile time and adjust as follows:

add 33 seconds for your pace for a 5K
multiply by 1.15 for 10K pace
multiply by 1.2 for half marathon pace
multiply by 1.3 for marathon pace

Here's how to do the one mile time trial:

1. warm up with a slow one mile run
2. do a few acceleration-gliders (See my books Running Year Round Plan and Galloway Training Programs)
3. pace yourself as even as possible on each quarter mile
4. run about as hard as you could run for one mile--but no puking! (finish feeling that you couldn't have run more than a football field at the same pace)
5. keep walking after the time trial for 5 minutes, and jog a slow 1-6 miles, as needed for the mileage for that day

Predicting race performance:

Take your last 4 one mile time trials
Eliminate the slowest
Average the other three
Use the prediction formula for your race
Adjust for heat and humidity: slow down by 30 sec a mile for every 5 degree temperature increase above 60F
最后一句好坑爹，在新加坡跑步：
（30-15）/5×30=每mile慢1分30秒