Carbohydrate calculator

UK advice is for about half your energy to come from them, mostly from starchy, wholegrain foods. Here it is in grams, with the sugar and fibre that go with it.

Your details

Sex
Your daily calories (leave blank for the NHS guide)
Training (optional)
Body weight (for training days)
Carbohydrate you ate today (optional)
Fibre you ate today (optional)

No number to hand? Leave it blank and we use 2,000 kcal for women and 2,500 kcal for men.

Carbohydrate at 2,000 kcal

250 g

about half your energy

  • Of which free sugars, at most25 g
  • Fibre to aim for30 g
  • As kcal1,000 kcal

UK advice is for about half your energy to come from carbohydrate, mostly wholegrain and starchy foods, fruit and veg. Free sugars are the ones to keep small.

The working

Half your energy, in grams

Carbohydrate has about 4 kcal a gram. At the NHS guide of 2,000 kcal: half is 1,000 kcal, divided by 4 is 250 g a day. Free sugars should be no more than 5% of energy, which is 25 g at 2,000 kcal, and never more than 30 g for adults.

Good carbs

Where the grams come from

  • Wholegrain bread, pasta, rice and oats: slower to digest and full of fibre
  • Potatoes with their skins on
  • Beans, lentils and peas, which bring protein too
  • Fruit, veg and milk, whose natural sugars do not count as free sugars

Food labels list "carbohydrate" with "of which sugars" underneath. That sugars line includes milk and fruit sugars, so it overstates free sugars for things like yogurt.

Low carb?

What the evidence says

SACN reviewed the evidence in 2015 and kept carbohydrate at about half of energy, while cutting the advice on free sugars and raising fibre to 30 g. Lower carb diets can work for weight loss for some people, but tend to be lower in fibre, which matters for gut and heart health.

Training days

Grams per kg, the sports way

Sports dietitians set carbohydrate per kg of body weight for training days (Thomas, Erdman and Burke 2016): 3 to 5 g/kg for light or skill based training, 5 to 7 for about an hour a day, 6 to 10 for 1 to 3 hours of endurance work and 8 to 12 for 4 to 5 hours. A 60 kg runner doing 1 to 3 hours a day needs about 360 to 600 g, well above the 250 g half of energy guide at 2,000 kcal.

Add what you ate today to see it as a share of your energy, and your fibre against the 30 g aim: 18 g leaves 12 g to find, for example a bowl of porridge and a portion of beans.

Read with care

What this cannot tell you

  • DiabetesPeople using insulin need carb counting taught by their diabetes team.
  • Race day fuellingCarb loading and fuelling during long events are best planned with a sports dietitian; we show training day ranges only.
  • ChildrenChildren need energy for growth; ask a health visitor or GP.

Questions

Common questions

How many carbs should I eat a day?

About half your energy, so roughly 250 g at 2,000 kcal or 310 g at 2,500 kcal. Most should be starchy and wholegrain.

Are carbs fattening?

No more than any other food. Gram for gram, carbohydrate has less than half the calories of fat. What we add to them (butter, creamy sauces) often matters more.

What counts as a free sugar?

Sugar added to food or drink, plus the sugar in honey, syrups, fruit juice and smoothies. Sugar inside whole fruit, veg and plain milk does not count.

Sources

Last checked 21 October 2026. Spotted something wrong? Tell us and we will fix it.

If food feels hard

If eating, weight or food is on your mind a lot, you are not alone. Your GP can help, and Beat has a free helpline on 0808 801 0677 (England, weekdays 3pm to 8pm).

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