Cool Wolfram|Alpha Use
Go to www.wolframalpha.com and enter the amount of time you spent running on a run where you felt good the whole time—I entered “running for 45 minutes.”

This should pop up. Just fill out the information. (This is normally used for calculating how far you went, but we’re interested in something else, just hold on.)
After you’ve filled it out, just put the cursor in the pace box and hit enter. A bunch of new information should appear below! Including…

Race time predictions! This gives you an estimation of how to pace yourself for any race based on how fast you ran the distance you entered!
REBLOG AND SHARE THIS GLORIOUS INFORMATION!