Race tools answer planning questions. The race time predictor estimates what a recent result might be worth at another distance using Riegel. Race equivalents invert Daniels VDOT instead. Required performance asks Riegel backwards: what time do you need at a known distance to hit a goal.
Split tools are arithmetic. Even kilometre and mile tables lock the interval. Negative, positive, and progressive profiles change pace during the race and still sum to the finish. Half and marathon pace bands print both kilometre and mile columns.
Equivalent performances assume similar training and conditions. Split tables assume the profile you typed. Heat, hills, and crowds are not in the math. Full formulas live on the methodology page.