Fitness Calculators
Repit's fitness calculators are free online tools that estimate your daily calorie needs (TDEE), one-rep max, Fat-Free Mass Index (FFMI) and macro split, using established formulas such as Mifflin-St Jeor and Brzycki.
TDEE Calculator
TDEE Calculator
Calculate your Total Daily Energy Expenditure
1RM Calculator
1RM Calculator
Estimate your One Rep Max
FFMI Calculator
FFMI Calculator
Calculate your Fat-Free Mass Index
Macro Calculator
Macro Calculator
Calculate your daily macronutrient needs
Results are estimates for general education, not medical advice. Talk to a doctor or registered dietitian before changing your diet or training, especially if you have a health condition.
Frequently Asked Questions
What is TDEE?
TDEE (Total Daily Energy Expenditure) is the total number of calories your body burns in a day, including basal metabolic rate, physical activity, and digestion. Knowing your TDEE helps you plan your diet for weight loss, maintenance, or muscle gain.
How is 1RM calculated?
1RM (One Rep Max) is calculated using the Brzycki formula: 1RM = weight / (1.0278 - 0.0278 × reps). This provides an estimate of the maximum weight you can lift for one repetition, which is useful for planning your strength training.
What is a good FFMI score?
FFMI (Fat-Free Mass Index) measures muscle mass relative to height. Scores below 18 are below average, 18-20 is average, 20-22 is above average, 22-25 is excellent, and above 25 is elite level. Natural athletes rarely exceed 25.
How should I distribute my macros?
Macro distribution depends on your goal. For fat loss: higher protein (35%) helps preserve muscle. For muscle building: moderate protein (30%) with higher carbs fuels workouts. For maintenance: a balanced distribution works best.
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