Running Tools
Free calculators for pace, fueling, hydration, and race planning. No signup required.
Fueling Calculator
Core ToolBuild a minute-by-minute race-day fueling plan with your exact gel brand. The tool that started it all.
Open tool →Race Time Predictor
NewEnter a recent race result and predict your finish time at any distance using the Riegel formula.
Open tool →Running Pace Calculator
NewCalculate pace, finish time, or distance. Enter any two and we solve for the third.
Open tool →Heat Adjustment Calculator
NewSee how temperature and humidity affect your race pace and fueling strategy.
Open tool →Hydration Calculator
NewEstimate your fluid and sodium needs based on body weight, duration, and conditions.
Open tool →