Carbohydrate Calculator
This calculator is for informational purposes only and is not a substitute for professional medical advice. Consult a healthcare provider for personal health decisions.
Carbs (g) = TDEE × carb% ÷ 4
How Carbohydrate Needs Are Calculated
Daily carbohydrate requirements start with Total Daily Energy Expenditure (TDEE). First calculate BMR using Mifflin-St Jeor: male BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) + 5; female BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) − 161. TDEE = BMR × activity multiplier (sedentary 1.2 through very active 1.9). Adjust for goals: maintenance uses TDEE; weight loss subtracts 500 kcal; weight gain adds 500 kcal.
Carbohydrates provide 4 kcal per gram. Daily carb grams = (target calories × carb percentage) ÷ 4. Diet approaches use different carb percentages: moderate carb 45–55%, low carb 25–35%, keto 5–10%, high carb for athletes 55–65%. Each approach yields a min–max gram range reflecting the percentage span.
Example: 2,500 kcal target at 50% carbs = 1,250 kcal from carbs = 312.5 g/day. Dividing by 3 gives per-meal targets; dividing by 4 spreads intake across three meals plus a snack. Athletes and endurance trainers often need higher carb percentages to replenish glycogen; keto approaches drastically restrict carbs to induce ketosis under medical supervision.
Food equivalents illustrate gram targets: one bread slice ~15 g, one cup cooked rice ~45 g, one medium banana ~27 g. Quality matters — whole grains, fruits, vegetables, and legumes provide fiber and micronutrients beyond refined sources.
Carb needs vary with training intensity, insulin sensitivity, and personal tolerance. Pair with protein and fat calculators for complete macronutrient planning. Consult a dietitian for medical conditions like diabetes before major dietary changes.
Examples
| Example | Result |
|---|---|
| Male 30y, 80 kg, 180 cm, moderate | TDEE ~2,759 kcal → moderate carbs ~310–379 g |
| 2,000 kcal, 50% carbs | ~250 g/day |
| Keto at 2,000 kcal (7.5%) | ~38 g/day |
| Athlete 3,000 kcal, 60% carbs | ~450 g/day |
Frequently asked questions
Moderate diets typically use 45–55% of calories from carbs. On 2,000 kcal that's 225–275 g/day. Athletes may need more; keto diets use under 10%.
A widely used BMR formula based on weight, height, age, and sex. TDEE multiplies BMR by an activity factor to estimate total daily calorie burn.
Weight loss primarily requires a calorie deficit. Low-carb diets can aid some people through appetite reduction, but total calories determine fat loss.