Would you find it useful? 
Race time prediction based on a reference run you are already confident.
May add it to "Miles O'Meter" frame in v2

Runna certainly have the data but I think their predictions are kind of straightline, which isn't so useful. 

I'm trying to figure out how my 5K times at 600m on nothing but hills are going to translate to a flat half at sea level! Can't wait to see the actual data.

CEO of TrueTribe. Partner in UmbrianGold. Farmer.

Send me your time on 5k and I will reply with the screenshot. Let’s see if it works.

My best 5k is 26:26. What will my half time be???

MO'M v2:  now with race time predictions

please give honest brutal feedback, I'm planning to add "training plans" for v3, but if no-one is using it or finding it useful, I can just stop developing it.

https://running-pace.vercel.app/

I’ve casted the frame today: https://warpcast.com/alor/0xccd2b5c just insert “5k in 26:26” and press predict

This is your estimated curve:

@prmurphy since your 5k was hilly, I’ll say a sub2 half is in your cords

In theory you can do it. But I would need another race before November to be more precise. I’ve found (on myself) that the prediction curve for the marathon to be too optimistic. 
While I’m pretty consistent to the curve for 5k 10k and half, for the marathon the actual pace is slower than predicted. 
So this time I’m not sure if you can do a sub4 based on this result for the half

Most accurate prediction. Runna had me at over 2 hours. Actual time 1:55:51. 

Next prediction: will I manage a sub 4 in NY in November? My last NY (when I could do halfs in 1:45) was 3:50.  But that was in 1998, when I was significantly younger.