Carbohydrate Calculator
Find a daily carbohydrate target scaled to your body weight and training load.
Your details
Moderate exercise 3–5 days a week
About an hour a day
This is an estimate from a published formula, not medical advice. Individual results vary widely. Talk to a doctor or registered dietitian before making changes to your diet, training or medication.
This works out a daily carbohydrate target in grams from your calorie intake and activity level.
Carbohydrate is best set last, after protein and a fat floor, and this explains why.
How much carbohydrate you need
Carbohydrate provides 4 calories per gram and is the body's preferred fuel for higher-intensity work. It is also the macronutrient with the widest sensible range, which confuses people.
The official guidance, the Acceptable Macronutrient Distribution Range, is 45-65% of calories. On 2,000 calories that is anywhere from 225 g to 325 g — a 100 g span, and both ends are considered fine.
The range is wide because carbohydrate is genuinely the flexible macro. Protein has a requirement set by body weight. Fat has a floor set by hormonal function. Carbohydrate takes whatever calories are left, and how much that is depends on how much you train and what you enjoy eating.
248 g sits comfortably inside the 225-325 g AMDR band. Change the calorie target and this is the number that moves.
What to enter
- Calorie target
- From TDEE adjusted for your goal. Carbohydrate is calculated out of this.
- Protein and fat targets
- Set these first. Protein from body weight, fat to a floor of about 0.5-0.8 g/kg.
- Activity level
- Endurance athletes need considerably more carbohydrate, often 5-10 g/kg on heavy training days.
- Preference
- Within the range, higher-carb and lower-carb approaches both work. Adherence decides which is better for you.
Carbohydrate needs by situation
- AMDR general guidance
- 45-65% of calories. Very wide, and deliberately so.
- Sedentary
- The lower end is usually plenty. There is no requirement to fill the range.
- Endurance training
- 5-10 g/kg on heavy training days. This is where carbohydrate genuinely matters most.
- Low-carb / [keto](/health/keto-calculator)
- Under 50 g, or under 20 g for reliable ketosis. Well below the AMDR by design.
- Minimum for brain function
- About 130 g a day, though the body can produce glucose from other sources when intake is lower.
What this assumes
The AMDR is a broad population range, not a prescription. Individual needs vary enormously with training volume.
Carbohydrate quality matters alongside quantity. 250 g from vegetables, fruit and whole grains behaves very differently from 250 g of refined sugar.
How to calculate your daily carbohydrate target
Set protein and fat first, then divide the remaining calories by four.
- protein × 4
- Protein at 4 calories per gram
- fat × 9
- Fat at 9 calories per gram
- ÷ 4
- Carbohydrate is also 4 calories per gram
Set protein from body weight. 1.6-2.2 g/kg. At 70 kg and 1.8 g/kg that is 126 g, or 504 calories.
Set the fat floor. At least 0.5-0.8 g/kg. At 70 kg and 0.8 g/kg that is 56 g, or 504 calories.
Divide the remainder by four. 2,000 − 504 − 504 = 992 calories, so 248 g of carbohydrate.
Adjust with training volume. Heavy endurance days justify more; rest days need less. This is the macro to move, not protein.
See a worked example: the range, and a number inside it
- Calories
- 2,000
- Body weight
- 70 kg
AMDR: 45% of 2,000 = 900 cal = 225 g. 65% = 1,300 cal = 325 g.
Setting protein and fat first: 126 g protein and 56 g fat leaves 992 calories, which is 248 g.
That sits comfortably inside the band, which is what you would expect if the range is sensible.
An endurance athlete at 70 kg training hard might target 6 g/kg, which is 420 g — well above the AMDR, and appropriate for the workload.
248 g, within a 225-325 g range
Frequently asked questions
The general guidance is 45-65% of calories, which is 225-325 g on a 2,000-calorie diet. That is a wide range, and both ends are fine.
A more useful approach is to set protein and fat first and let carbohydrate take the remainder. It lands inside the range naturally and adjusts itself when your calories change.
Total carbohydrate minus fibre and sugar alcohols, on the basis that neither is fully digested and absorbed as glucose.
It is a useful concept for low-carb and keto tracking. For a general diet, tracking total carbohydrate and aiming for adequate fibre is simpler and works just as well.
Not strictly. There is no essential carbohydrate requirement in the way there are essential fatty acids and amino acids; the body can make glucose from other sources.
But performance in higher-intensity training is genuinely better with carbohydrate available, and carbohydrate foods carry fibre and micronutrients that are harder to get elsewhere.
No. Weight change follows the calorie deficit, not the macronutrient split. Controlled trials matching calories and protein find similar fat loss across a wide range of carbohydrate intakes.
Lower-carb approaches suit some people because of appetite control, and higher-carb approaches suit others. The one you can actually maintain is the effective one.
Considerably more: commonly 5-10 g/kg on heavy training days for endurance athletes, which is 350-700 g at 70 kg.
This is where carbohydrate matters most. Muscle glycogen is the limiting fuel for sustained high-intensity work, and under-fuelling it costs performance directly.
The distinction is looser than it is usually presented. Fibre content, food processing and what else is eaten alongside all affect the glucose response more than the simple/complex label does.
The practical version: prioritise whole foods with fibre, and keep refined sugar modest. Around meals and training the differences matter much less than people assume.
Problems people actually run into
Setting carbohydrate first
Starting from a carbohydrate percentage leaves protein and fat to absorb whatever is left, and protein is the one that suffers.
Protein has a requirement set by body weight and fat has a physiological floor. Carbohydrate is the one with a wide safe range, which is exactly why it should be set last.
Cutting carbohydrate while training hard
Muscle glycogen fuels high-intensity work. Restricting carbohydrate sharply while maintaining hard training usually shows up as flat sessions and stalled progress.
If you want to eat low-carb, expect an adaptation period and consider timing what carbohydrate you do eat around training.
Results are estimates for general information only and are not professional financial, medical, or legal advice. Read our full disclaimer.
Last updated: September 4, 2026