Carbohydrate Calculator
Calculate your daily carbohydrate needs based on TDEE, activity level, and fitness goal. See grams, calories, and meal distribution.
Enter your details and click Calculate.
How Does the Formula Work?
The carbohydrate calculator estimates your daily carb needs by first calculating your Total Daily Energy Expenditure (TDEE) using the Mifflin-St Jeor BMR equation, then applying a carbohydrate percentage based on your dietary goal. The result shows grams per day, calories from carbs, grams per kilogram of body weight, fiber recommendations, and a suggested meal distribution.
Male: 10 × weight + 6.25 × height − 5 × age + 5
Female: 10 × weight + 6.25 × height − 5 × age − 161
Step 2: TDEE = BMR × Activity Factor
Step 3: Carb Calories = TDEE × Carb Percentage
Step 4: Carb Grams = Carb Calories ÷ 4
Carb Percentage by Goal:
Low Carb / Keto: 10–25% (midpoint 17.5%)
Moderate / Weight Loss: 25–40% (midpoint 32.5%)
Standard / Balanced: 45–55% (midpoint 50%)
High Carb / Performance: 55–65% (midpoint 60%)
Example: 70kg male, moderate activity, standard goal
BMR = 1649 kcal → TDEE = 2556 kcal
Carbs = 2556 × 50% ÷ 4 = 319g/day
Understanding Carb Goals
The Standard/Balanced option (45–55%) follows guidelines from the Dietary Guidelines for Americans and WHO, suitable for most healthy adults. The Moderate option (25–40%) is commonly used for gradual weight loss, reducing carbs while maintaining adequate energy for daily activities. Low Carb/Keto (10–25%) drastically reduces carbohydrates to promote ketosis — this approach requires careful planning to ensure adequate nutrition and should ideally be supervised by a healthcare provider. High Carb/Performance (55–65%) supports endurance athletes and those with high training volumes who need maximum glycogen stores.
Carbs Per Kilogram of Body Weight
Sports nutrition often expresses carb needs per kilogram rather than as a percentage. General guidelines: 3–5 g/kg for moderate exercise, 5–7 g/kg for endurance training, 7–10 g/kg for extreme endurance or multiple daily sessions. The calculator shows this metric alongside the percentage-based recommendation so you can cross-reference with sport-specific guidelines.
Fiber Recommendations
The calculator includes USDA Dietary Reference Intake (DRI) fiber recommendations, which vary by age and gender. Adequate fiber intake supports digestive health, blood sugar regulation, and cardiovascular health. When reducing carbohydrate intake on low-carb diets, it is important to prioritize fiber-rich carb sources (vegetables, nuts, seeds) to maintain adequate fiber intake even at lower total carb levels.
Meal Distribution
The suggested distribution (Breakfast 25%, Lunch 30%, Dinner 30%, Snacks 15%) is a common pattern, but not the only valid approach. Some people prefer equal meals, others prefer front-loading carbs around workouts. Athletes often consume extra carbs before and after training. The distribution is a starting point — adjust based on your schedule, training times, and personal preferences.
Tips & Recommendations
Low-carb/keto, moderate, standard, and high-carb — each with scientifically-based percentage ranges for different objectives.
See your carb intake relative to body weight — useful for cross-referencing with sport-specific nutrition guidelines.
Carbs distributed across breakfast (25%), lunch (30%), dinner (30%), and snacks (15%). Adjust to match your schedule.
Personalized fiber recommendations by age and gender. Important even on low-carb diets — prioritize fiber-rich sources.
Frequently Asked Questions
How many carbs do I need per day?
It depends on your TDEE and goal. Standard diets recommend 45–55% of calories from carbs. For a 2000 kcal diet, that is 225–275g. Low-carb diets drop to 10–25% (50–125g), while high-performance athletes may need 55–65%.
What are the carb goal options?
Low Carb/Keto (10–25%), Moderate/Weight Loss (25–40%), Standard/Balanced (45–55%), and High Carb/Performance (55–65%). The calculator uses the midpoint of each range.
How is TDEE calculated?
Using the Mifflin-St Jeor BMR formula multiplied by an activity factor: Sedentary ×1.2, Light ×1.375, Moderate ×1.55, Active ×1.725, Very Active ×1.9.
What is the meal distribution?
Carbs are distributed as: Breakfast 25%, Lunch 30%, Dinner 30%, Snacks 15%. This is a general guideline — adjust based on your schedule and preferences.
How much fiber should I eat?
USDA recommends 25–30g/day for women and 30–38g/day for men (adults under 50). The calculator shows personalized fiber recommendations based on your age and gender.
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