Tools

Free calculators for training and fueling. Each one runs in your browser, saves nothing, and cites the research behind its numbers.

• Endurance sports Race fuel calculator. Your carb load, race breakfast and carbs per hour, from your weight and finish time.
• General fitness Protein calculator. How much protein a day, and per meal, for your body weight and goal.
• General fitness Sweat rate calculator. Weigh yourself before and after a session to find how much you sweat per hour.
• HYROX HYROX split planner. Your run pace and a suggested time for each of the eight stations, for your target finish.
• Running Pace calculator and race time predictor. Your pace from a recent race, and predicted 5K, 10K, half and marathon times.
• General fitness Calories burned calculator. Estimated calories for a workout, from your weight, the activity, your speed and how long you went.
• Weight training One-rep max calculator. Estimate your 1RM from a hard set, get training weights for any rep count, and see what plates to load.
• General fitness Meal prep calculator. How much to cook for a batch of meals, what goes in each container, and a grocery list.
• Running Heat and humidity pace calculator for runners. Enter a US ZIP code, or the temperature and humidity from your weather app, to see roughly how much the heat may slow your running pace.
• Endurance sports Carb loading calculator. Your two-day carb target and a six-meal plan of everyday foods, for your body weight.
• Running Caffeine calculator for runners. A starting caffeine dose for your weight, in cups of coffee, espresso or tea, and when to take it.
• Running Age grade calculator. Your age-graded score and equivalent time, for road races from 1 mile to 50 miles.
• Running Taper calculator. A day-by-day plan that cuts your running before a race while keeping your pace and your number of runs.
• General fitness Wake-time shifter for morning workouts. A day-by-day plan to wake up earlier for a morning run or workout, moving your bedtime with it so you keep your sleep.
• General fitness Body fat calculator. Estimate your body fat percentage with a tape measure, and compare it with an estimate from your height and weight.