Macro Calculatorv1.0.0

Use the Macro Calculator to estimate daily energy needs and convert them into a practical macronutrient plan. Provide age, sex, height, weight, and activity level to compute Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE). Choose a goal to maintain, lose, or gain, then apply a macro distribution preset or enter a custom split that totals 100%.

Follow these steps for accurate, repeatable results:

• Select units (Imperial or Metric). Enter height and weight. The tool converts values automatically when you switch units.
• Enter age and choose sex. Select an activity level that best matches your routine.
• Pick a BMR formula: Mifflin–St Jeor (uses height, weight, age, sex) or Katch–McArdle (uses estimated body fat to compute lean body mass). If using Katch–McArdle, enter body fat percent.
• Choose a goal: Maintain, Lose, or Gain. The calculator adjusts calories accordingly.
• Select a macro preset (Balanced, Low Fat, Low Carb, High Protein) or select Custom to enter protein %, carbs %, and fat % that sum to 100.
• Choose your results unit (Calories or Kilojoules) and click Calculate. Use Reset to restore defaults.

Formulas and logic (plain text for easy copying):

• Mifflin–St Jeor (male): BMR = 10·W + 6.25·H − 5·A + 5
• Mifflin–St Jeor (female): BMR = 10·W + 6.25·H − 5·A − 161
• Katch–McArdle: LBM = W × (1 − BF%); BMR = 370 + 21.6·LBM
• Activity factor (TDEE): Sedentary 1.20, Somewhat Active 1.375, Active 1.55, Very Active 1.725, Intense 1.90
• TDEE = BMR × activity factor
• Goal calories: Maintain = TDEE; Lose = TDEE − 500; Gain = TDEE + 500
• Macro grams: Protein g = (Calories × Protein%) ÷ 4; Carbs g = (Calories × Carbs%) ÷ 4; Fat g = (Calories × Fat%) ÷ 9
• Sugar limit ≈ 10% of calories: Max Sugar g = (Calories × 0.10) ÷ 4
• Saturated fat limit ≈ 10% of calories: Max Sat Fat g = (Calories × 0.10) ÷ 9
• kJ conversion: Kilojoules = Calories × 4.184
• Unit conversions: 1 in = 2.54 cm; 1 ft = 30.48 cm; 1 lb = 0.453592 kg

Apply the Macro Calculator across fitness, nutrition planning, and everyday health goals. Translate calorie targets into clear macro grams that you can act on when shopping, meal prepping, or logging food. Adapt your plan as your training volume, body composition, or objectives change.

• Weight maintenance: Keep energy intake aligned with TDEE during steady training phases. Use a Balanced preset to support overall performance and recovery.
• Fat loss phases: Reduce calories to TDEE − 500 and use a High Protein or Low Carb split to support satiety and lean mass while in a deficit.
• Muscle gain periods: Increase calories to TDEE + 500 and select a split that supports training volume, such as High Protein with moderate carbohydrates.
• Endurance training: Choose a higher carbohydrate split to fuel longer sessions, while keeping protein sufficient for recovery.
• Low-fat emphasis: Use the Low Fat preset to prioritize carbohydrates and protein while keeping dietary fat controlled within recommended ranges.
• Custom nutrition strategies: Enter a custom macro ratio to match a coach’s plan or a medical recommendation, ensuring the three percentages total 100.
• Meal planning and grocery lists: Convert daily grams into per-meal targets to streamline shopping and batch cooking.
• Progress check-ins: Recalculate after weight changes, new training blocks, or shifts in activity level to keep targets current.
• Education and comparisons: Compare how Mifflin–St Jeor and Katch–McArdle affect BMR estimates, or how activity factors change TDEE.

This tool is intended for informational and educational purposes only. It does not provide medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider for any health-related concerns or decisions.