Enter in the distance you are running. You can choose your units. Enter the start time of the race. Put in targeted goals for calories, carbohydrates, electrolytes and fluids per hour. Then add the distance to each aid station and projected pace. This calculator will provide estimated arrival time to each aid station which is handy for crew. It will also project the amount of nutrition and hydration you will need between aid stations based on the distance and your projected pace! Happy nerding out!