Free Running Calculators & Tools

Build a minute-by-minute race-day fueling plan with your exact gel brand. The tool that started it all.

Enter a recent race result and predict your finish time at any distance using the Riegel formula.

Calculate pace, finish time, or distance. Enter any two and we solve for the third.

See how temperature and humidity affect your race pace and fueling strategy.

Estimate your fluid and sodium needs based on body weight, duration, and conditions.

Calculate your pre-race carb loading targets by race type, body weight, and experience level.

Compare gels by carbs, price, and value. Sort, filter, and find the best gel for you.