Carbohydrate Calculator
Calculate your recommended daily carbohydrate intake based on calorie target, activity level and fitness goal.
How to use the Carbohydrate Calculator
- Enter your inputs into the Carbohydrate Calculator above.
- Results update instantly as you type — no submit button needed.
- Adjust any value to see how the result changes in real time.
The carbohydrate calculation
Carb grams = (Total calories × carb %) / 4 kcal per gram
Carbs typically make up 45–65% of calories per dietary guidelines, dropping to 20–40% on low-carb plans. For active individuals: 3–5 g/kg/day moderate, 5–7 g/kg/day endurance training, 7–10+ g/kg/day intense endurance.
Worked example
A 2,500 cal/day intake at 50% carbs: 1,250 cal from carbs ÷ 4 cal/g = 312 g/day. An 80 kg endurance athlete at 6 g/kg = 480 g of carbs daily.
Frequently asked questions
Are all carbs the same?
No — fiber-rich whole-food carbs (vegetables, fruit, oats) digest slowly and provide steady energy. Refined carbs and added sugars digest fast and trigger larger glucose/insulin spikes. Total grams matter for energy balance; quality matters for satiety and health.
What's a low-carb diet?
Below 130 g/day is sometimes called low-carb; below 50 g/day is ketogenic. Both can produce weight loss when total calories are managed; neither is universally better than higher-carb approaches.
Do athletes need more carbs?
Yes — carbs are the primary fuel for moderate-to-high intensity exercise. Endurance athletes performing 1+ hour daily often benefit from 5–7 g/kg/day to support glycogen stores.