Quick answer
How many carbs should I eat a day?
For general health, carbohydrates should supply 45 to 65% of your calories, the range set by the National Academies: about 225 to 325 g on a 2,000-calorie diet. Low-carb diets usually mean under 130 g a day, and keto means roughly 20 to 50 g of net carbs. Athletes in hard training may need 5 to 10 g per kg of body weight. Whatever the number, get most of it from high-fibre foods.
On this page
How to use the carbohydrate calculator
- Enter your sex, age, height and weight in metric or imperial.
- Pick your activity level and goal (lose, maintain or gain). This sets your daily calories.
- Choose a diet style. Balanced is right for most people; keto and low carb suit people who find fewer carbs easier to stick to; high carb suits endurance training.
- Read your carbs in grams per day, plus the share of calories, a per-meal split and your fibre target. Results update as you type.
How the carb calculator works
Carb needs depend on how much energy you use, so the calculator starts from your calories rather than a one-size-fits-all number.
- Daily calories. Your resting burn from the Mifflin-St Jeor equation, multiplied by your activity level, then adjusted for your goal (−20% to lose, +10% to gain).
- Carb share. Your diet style sets the percentage of those calories that comes from carbohydrate.
- Grams. Carbohydrate has 4 calories per gram, so carb calories are divided by 4. Keto is capped at 20 to 50 g of net carbs whatever your calories, because ketosis depends on the absolute amount.
| Diet style | Carbs | Who it suits |
|---|---|---|
| Keto | 20–50 g net a day (about 5%) | People aiming for ketosis, or who find very low carb easiest to stick to |
| Low carb | About 20% of calories, under 130 g | Weight loss where fewer starches and sugars helps appetite control |
| Balanced | About 50% (healthy range 45–65%) | Most people, and the range health guidelines recommend |
| High carb | About 60% of calories | Endurance athletes and people training hard most days |
Carbs per day by calorie level
If you already know your calorie target, this table gives the carb grams for each style. Use the calorie calculator if you don’t.
| Daily calories | Keto | Low carb (20%) | Balanced (50%) | High carb (60%) |
|---|---|---|---|---|
| 1,500 | 20–50 g | 75 g | 188 g | 225 g |
| 1,800 | 20–50 g | 90 g | 225 g | 270 g |
| 2,000 | 20–50 g | 100 g | 250 g | 300 g |
| 2,500 | 20–50 g | 125 g | 313 g | 375 g |
| 3,000 | 20–50 g | 150 g | 375 g | 450 g |
Carbs for athletes and active people
Hard training runs on stored carbohydrate (glycogen). Sports nutrition guidance sets carb needs by body weight and training volume rather than by percentage:
| Training load | Carbs per kg body weight | 70 kg person |
|---|---|---|
| Light or skill-based | 3–5 g/kg | 210–350 g |
| Moderate, about 1 hour a day | 5–7 g/kg | 350–490 g |
| High, 1–3 hours a day endurance | 6–10 g/kg | 420–700 g |
If you train hard and choose low carb, expect performance in long or high-intensity sessions to drop. Putting most of your carbs in the meals before and after training is a simple compromise.
Net carbs vs. total carbs
Total carbs is the figure on a nutrition label: starch, sugar and fibre together. Net carbs subtract the fibre (and some sugar alcohols), because fibre is not digested into glucose.
Net carbs matter mostly on keto, where the limit is tight. A cup of raspberries has about 15 g of total carbs but 8 g of fibre, so it costs only about 7 g net. For balanced and high-carb eating, track total carbs and simply make sure plenty of them come with fibre.
Carb quality: simple vs. complex
Limit: refined and sugary
White bread and pastries, sweets, sugary drinks and juice. They digest fast, are easy to overeat and bring little fibre.
Build on: whole and high-fibre
Oats, brown rice, quinoa, potatoes, beans, lentils, fruit and vegetables. They digest slowly and keep you fuller for longer.
A large Lancet review found that people who ate 25 to 29 g of fibre a day had lower rates of heart disease, stroke, type 2 diabetes and bowel cancer than those who ate less. A practical target is about 14 g of fibre per 1,000 calories.
Good carb sources, per serving
| Food | Serving | Carbs | Fibre |
|---|---|---|---|
| Rolled oats | 40 g dry | 27 g | 4 g |
| Brown rice, cooked | 1 cup | 45 g | 3.5 g |
| Quinoa, cooked | 1 cup | 39 g | 5 g |
| Lentils, cooked | 1 cup | 40 g | 16 g |
| Sweet potato, baked | 1 medium | 24 g | 4 g |
| Banana | 1 medium | 27 g | 3 g |
| Apple | 1 medium | 25 g | 4.4 g |
| Broccoli, cooked | 1 cup | 11 g | 5 g |
Carbs and weight loss
Cutting carbs often produces fast early weight loss, but much of that first week is water. Each gram of stored glycogen is held with about three grams of water, so emptying those stores shows up on the scale straight away.
The lasting fat loss comes from the overall calorie deficit, not from carbs being uniquely fattening. Trials that match calories find low-carb and low-fat diets lose similar amounts of fat. Choose the carb level you can stick to, keep protein high with the protein calculator, and set your full split with the macro calculator.
Frequently asked questions
How many carbs should I eat a day to lose weight?
There is no single figure, because weight loss is driven by the calorie deficit rather than the carbohydrate number. People lose weight successfully anywhere between 50 g and 250 g a day. Set your goal to “lose” and the calculator works from a deficit. Where the carbs come from matters more than the exact number: whole grains, pulses, fruit and vegetables carry fibre that keeps you full.
What are net carbs?
Net carbs are total carbohydrate minus fibre (and minus some sugar alcohols). Fibre is not digested into glucose, so it does not raise blood sugar the same way. Keto dieters usually track net carbs. A cup of raspberries has about 15 g of total carbs but 8 g of fibre, so only about 7 g net.
How many carbs can I eat and stay in ketosis?
Most people need to stay under 20 to 50 g of net carbs a day, and the exact threshold is individual. Activity level, muscle mass and how long you have been keto-adapted all shift it. The first week often brings headaches and fatigue, usually from sodium and fluid loss, which is why electrolytes help so much at the start.
What is the minimum amount of carbs I need?
The recommended dietary allowance is 130 g a day for adults, based on the glucose the brain uses. Your liver can make glucose from protein and fat, which is why very low-carb diets are possible, but most people feel and train better above that level, and it is hard to reach fibre targets without some carbohydrate foods.
Are carbs bad for you?
No. Trials comparing low-carb and low-fat diets at matched calories find broadly similar fat loss, which tells you carbohydrate itself is not the problem. The useful distinction is quality: refined carbs and sugary drinks are easy to overeat, while whole grains, legumes, fruit and vegetables are consistently linked to better health outcomes.
Is keto safe long-term?
Keto can be safe for many healthy adults, but it is restrictive, and it tends to be low in fibre and some vitamins found in fruit, grains and legumes. Long-term adherence is hard for most people. If you have diabetes, kidney disease or take blood pressure or glucose-lowering medication, talk to your doctor first.
How many carbs do athletes need?
It scales with training. Sports nutrition guidance suggests about 3 to 5 g per kg of body weight on light training days, 5 to 7 g/kg for about an hour a day of moderate training, and 6 to 10 g/kg for 1 to 3 hours of hard endurance work.
What is carb cycling and does it work?
Carb cycling means eating more carbohydrate on training days and less on rest days, keeping weekly calories where you want them. The direct evidence for an advantage over eating the same amount every day is thin. It can still help adherence, because it puts your food where your training is.
How much fibre should I eat?
About 14 g per 1,000 calories, which is roughly 25 g a day for women and 30 to 38 g for men. Large reviews link eating 25 to 29 g or more a day to lower rates of heart disease, type 2 diabetes and bowel cancer. The calculator shows a fibre target based on your calories.
Sources
- National Academies. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids, 2005.
- Reynolds A, et al. Carbohydrate quality and human health: a series of systematic reviews and meta-analyses. The Lancet, 2019.
- Thomas DT, et al. Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the ACSM: nutrition and athletic performance. J Acad Nutr Diet, 2016.
- Mifflin MD, St Jeor ST, et al. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr, 1990.
- U.S. Department of Agriculture and HHS. Dietary Guidelines for Americans, 2020–2025.
This calculator gives estimates for healthy adults and is for information only. It is not a diagnosis or a substitute for advice from a doctor or registered dietitian.