Macro Calculator for Runners,
CrossFit, Hyrox & Triathlon
Use this athlete calorie calculator to find your BMR, TDEE, and sport-specific protein, carb, and fat targets in under a minute. Built for runners, CrossFit-style training, Hyrox, triathlon, fitness, and football athletes — with presets tuned to each sport's actual energy demands.
Quick presets — pick your sport
Balanced split for strength work, circuits, and conditioning.
How it works
Athlete calorie calculator formulas, tuned by sport.
Most calorie calculators are built for the general population. This one is tuned for athletes who train more than three times a week and need macro targets that reflect their actual sport demands — not a one-size-fits-all average.
BMR via Mifflin-St Jeor
The most validated formula for estimating resting metabolic rate from weight, height, age, and sex.
TDEE from activity level
Your BMR is multiplied by a training-load factor (1.2 to 1.9) to get your true daily burn.
Goal adjustment
We add or remove 150–350 kcal depending on whether you're cutting, maintaining, bulking, or fuelling for performance.
Sport-specific macro split
Calories are distributed into protein, carbs, and fat using ratios validated for each sport's energy system.
Sport macro splits
FAQ
Common questions
What is the best macro calculator for runners, Hyrox, CrossFit, and triathlon?
A good athlete macro calculator should estimate BMR, convert it into TDEE with training load, then adjust calories and macros for the sport. FuelPrep uses sport-specific splits for running, Hyrox, CrossFit-style fitness, triathlon, and football instead of one generic protein, carb, and fat target.
How many calories should an athlete eat per day?
Daily calories depend on body size, sex, age, goal, and training volume. This athlete calorie calculator estimates your BMR with the Mifflin-St Jeor formula, multiplies it by your activity level to estimate TDEE, then adds or subtracts calories for cutting, maintenance, bulking, or performance.
What macros should runners and triathletes use?
Runners and triathletes usually need a carb-forward split to support mileage, long sessions, and recovery. FuelPrep starts running and triathlon calculations around 20% protein, 55% carbohydrates, and 25% fat, then converts those percentages into daily gram targets from your calorie estimate.
What macros should Hyrox and CrossFit athletes use?
Hyrox and CrossFit-style athletes need enough carbs for repeated high-intensity efforts plus enough protein for strength and recovery. FuelPrep uses higher-carb hybrid splits for Hyrox and a balanced high-protein fitness split for CrossFit-style training, then turns the split into grams of protein, carbs, and fat.