Carbohydrate Calculator
How many carbohydrates should you eat a day? This calculator estimates your daily calorie allowance from your age, build, and activity level, then shows the grams of carbohydrate that make up 40%, 55%, 65%, and 75% of that energy — for maintaining your weight, losing it, or gaining it.
+ Settings
- Exercise: 15-30 minutes of elevated heart rate activity.
- Intense exercise: 45-120 minutes of elevated heart rate activity.
- Very intense exercise: 2+ hours of elevated heart rate activity.
It is recommended that carbohydrates comprise 40-75% of daily caloric intake.
*The Institute of Medicine recommends American and Canadian adults to get 40% to 65% of their dietary energy from carbohydrates. The Food and Agriculture Organization and the World Health Organization jointly recommend 55% to 75% of total energy from carbohydrates, but only 10% directly from sugars.
Advertisement — In-Article
(Responsive Fluid)
What are carbohydrates?
Carbohydrates — carbs — are one of the three macronutrients that supply energy, alongside protein and fat. The body breaks them down into glucose, its preferred and most immediate fuel, and what isn't needed right away is stored as glycogen in the liver and muscles, or, once those stores are full, converted to fat. Although carbs are not classed as essential nutrients — the body can make glucose from other sources — they are its most efficient energy supply, and eating them in controlled amounts is linked with lower risk of cardiovascular disease, obesity, and type 2 diabetes.
Types of carbohydrates
Carbs are grouped as simple (mono- and disaccharides) or complex (oligo- and polysaccharides) — roughly, sugars versus everything else — and into three chemical families. Sugars are the simplest form, occurring naturally in fruit, vegetables, and dairy, and in processed form in candy, cakes, cookies, and sweet drinks. Starches are complex chains found in beans, vegetables, and grains. Fiber is the indigestible complex carb in fruit, vegetables, whole grains, and beans, and it is essential for healthy digestion. Many foods mix types, which is why the labels are a guide rather than a verdict: what matters most is how refined the food is. Complex, fiber-rich carbs digest slowly, keep you full longer, and carry other nutrients with them; simple, refined carbs — the "empty carbs" of soda, juice, and pastries — deliver energy with little else and are easy to over-consume.
How many carbs should I eat?
It depends on your size, activity, and goal — which is what the table above estimates. Two reference points frame the answer: the Institute of Medicine recommends a minimum of 130 grams a day for adults, and guideline ranges put carbohydrate at 40-75% of daily calories. Source quality matters as much as quantity. Good carbs are moderate in calories, high in nutrients and natural fiber, free of refined sugars and grains, and low in sodium, saturated fat, cholesterol, and trans fats — whole grains, vegetables, fruit, and beans are the textbook examples. Bad carbs invert that list: calorie-dense, nutrient-poor, built on refined grains and added sugars such as corn syrup and fruit juice concentrates. Very restrictive low-carb diets can suit particular people and situations, but they are a deliberate choice, not a default — and if you are considering a drastic change, a dietitian is worth consulting first. For the companion numbers, see the Protein Calculator and the Fat Intake Calculator.