The formula
How it works
Find how many grams of carbohydrate to eat each day, from your calorie target and the share of calories you want from carbs. Dietary guidelines suggest roughly 45–65% of calories from carbs for most people.
FAQ
How many carbs should I eat?
Guidelines suggest 45–65% of calories from carbohydrate for a balanced diet, but active people often go higher and low-carb diets go much lower. The right amount depends on your activity, goals and how your body feels.
Do carbs make you gain weight?
No single nutrient does — weight change comes from total calories. Carbs matter for energy and performance, and the type (whole grains and vegetables versus refined sugar) matters more for health than the raw amount.
What foods count as carbohydrates?
Grains, bread, pasta, rice, potatoes, fruit, legumes, milk and sugary foods all supply carbohydrate, though the mix of fiber, sugar and starch varies widely. Vegetables and whole grains bring fiber and nutrients alongside the carbs, while sugary and refined foods provide mostly quick energy.
What is the difference between simple and complex carbs?
Simple carbs, like sugar and white flour, are digested quickly and can spike blood sugar, while complex carbs, like whole grains and legumes, contain more fiber and digest more slowly. Most guidelines favor complex sources for steadier energy and better long-term health.
Should I subtract fiber to get net carbs?
Net carbs (total carbs minus fiber) is a common way to estimate the carbohydrate that actually affects blood sugar, since fiber is not digested the same way. This calculator gives total carbohydrate grams; subtract fiber yourself if you are tracking net carbs.
Do athletes need more carbohydrate?
Yes, endurance and high-intensity training burn through glycogen (stored carbohydrate) quickly, so active people often need carb intake toward the higher end of the range, sometimes above 65% of calories on heavy training days. Raising the percentage slider reflects that higher demand.
How low is a low-carb diet?
Low-carb approaches typically fall between 10% and 30% of calories from carbohydrate, while ketogenic diets go even lower, often under 10%. Moving the percentage slider toward the low end of this calculator’s range approximates a moderate low-carb target.
About the carbohydrate calculator
This calculator works out how many grams of carbohydrate you should eat in a day, based on your calorie target and the proportion of those calories you want to come from carbs. Carbohydrate is the body’s main fuel, especially for the brain and for exercise, so setting the right amount matters for energy and performance. Turning a percentage into grams makes the target something you can actually track on food labels.
How to use it
Enter your daily calorie target and slide to the share of calories you want from carbohydrate — around 50% is a common balanced choice. The calculator shows the equivalent grams per day. For example, 2,000 calories with 50% from carbs works out to 250 g of carbohydrate. Slide the percentage down for a lower-carb approach or up if you train hard and need more fuel.
The formula
Carbohydrate provides 4 calories per gram, so the grams are the carb calories divided by 4: , where is the percentage of calories from carbs. So half of 2,000 calories is 1,000 carb calories, which at 4 calories per gram is 250 g. Lowering the percentage or the calorie total both reduce the grams.
Where it is used
Endurance athletes use it to fuel training and races, where carbohydrate is the key energy source, while people managing blood sugar or following low-carb diets use it to cap their intake. Dietitians build carb targets into meal plans, and it slots directly into overall macro tracking alongside protein and fat. Getting carbohydrate right is central to both sports nutrition and everyday healthy eating.