If you are looking for a quick way to predict your next race time from a previous race, time trial or flat out training run, use this race time predictor to get an estimate. Just enter your previous race with the time, and choose the type of future race. You only need to enter the minutes field, but you can fine tune with hours and seconds too.
The calculations used are slightly different for marathons based off an average experience. Those with large amounts of miles might find they can perform better on marathon day and those with low consistency will perform slower.