This forecast is responsive to speed changes during the race. There are clear benefits for using current lap pace based forecast for finish time. E.g. first minutes are often slower, because of traffic, and thus average speed is clearly behind target in early race. Don't panic, stride faster when you can and you get quickly new realistic forecast from this App. Check values below. After 10 minutes still 41km left, but forecast shows that pace is good enough to finish under 3h. Average speed based estimates are also often too optimistic in late race. This App reacts quickly to pace drop and gives you early warning. It's again time to stride faster to reach your target! I made this forecast based on my own experience in long distance running. This is something that I have calculated always during the race to estimate how it will end up. In future, I let this App handle the calculations for me. I hope you find it useful too!