Training - Improved Riegel Calculator for Half Marathon to Marathon
In 1977, Pete Riegel devised a formula for predicting race times, based on your existing performances. The basic formula is t2 = t1 * (d2 / d1)1.06, but the "1.06" can be improved upon. Specifically, when converting from half marathon to full marathon, it often provides what feels like an unobtainable time. From an analysis of over a thousand runners, we have produced a calculator that will give you a more realistic calculation.
Enter your half marathon time here: