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Carb calculator

Enter your weight and how active you are, and get a rough daily range in grams, with everyday foods to show what that looks like. It's optional information, not a target.

By Anna Bromley, Healthcount Founder · Last reviewed 1 November 2026

The short answer

A carb calculator gives you a rough daily figure in grams. This one multiplies your weight by a number for how active you are, so a 70 kg (154 lb) person who exercises 3 to 5 days a week gets a range of 238 to 322 g a day. For comparison, UK food labels use a reference intake of 260 g of carbohydrate a day for adults, and US labels use a Daily Value of 275 g. Those are general reference figures, not personal targets. The NHS Eatwell Guide says starchy foods should make up just over a third of the food you eat.

References: NHS, The Eatwell Guide, UK reference intakes, FDA Daily Values. Read on 1 November 2026.

Your details
Three inputs, and your range updates instantly

Activity level

Goal

Your daily carb range
Lower
238g
Middle
280g
Upper
322g

A rough guide, not a target.

Worked examples

Three examples with the goal set to maintenance. Each one is the same sum the calculator does: your weight in kilograms times the figure for your activity level, with a range 15% either side.

Worked examples of the carb calculator at the maintenance setting
ExampleThe sumRough range a day
60 kg (132 lb), little or no exercise60 x 2.5 = 150 g128 to 173 g
70 kg (154 lb), exercises 3 to 5 days a week70 x 4 = 280 g238 to 322 g
85 kg (187 lb), exercises 6 to 7 days a week85 x 5 = 425 g361 to 489 g

Weight in pounds or stones? The calculator converts it for you. Under your result, there's a panel that shows your middle figure as everyday foods.

How the numbers are worked out

The calculator uses grams of carbohydrate per kilogram of body weight: 2.5 g per kg if you barely exercise, then 3, 4 and 5 g, up to 6 g per kg for hard daily training. The weight loss setting takes 20% off and the muscle gain setting adds 20%. That's all those settings do. The range around the middle number is there because no single figure is exact.

These are rule-of-thumb figures, not a medical guideline. Treat the result as information, not a rule. You don't need a number to eat well, and it's fine to close this page and never think about it again. If you have diabetes or you're pregnant, ask your care team rather than relying on a calculator.

If numbers around food are hard for you

You don't need this page, and numbers are optional everywhere in Healthcount.

Frequently asked questions

How many carbs should I eat a day?
There's no single number. UK food labels use a reference intake of 260 g of carbohydrate a day for adults, and US labels use a Daily Value of 275 g, but those are general reference figures, not personal targets. The NHS Eatwell Guide says starchy foods should make up just over a third of the food you eat. The calculator on this page gives a rough range from your weight and how active you are, if you'd like one.
Do I need to cut carbs?
No. The NHS says starchy foods have an important role in a healthy diet, and that we should eat some every day. It suggests choosing wholegrain versions where you can and keeping the skin on potatoes for more fibre. If you have diabetes, your care team can tell you what's right for you.
Do I need fewer carbs on a GLP-1 like Mounjaro or Wegovy?
Not as a rule. The British Dietetic Association's guide for people on these medicines says to put protein, carbohydrates and some vegetables or fruit on your plate at every meal, and to choose foods high in fibre, such as wholegrain bread, brown rice and wholewheat pasta. Your portions may be smaller than before. A registered dietitian can help if you want something more personal.
How does this carb calculator work?
It multiplies your weight in kilograms by a figure for your activity level, from 2.5 g per kg if you barely exercise to 6 g per kg for hard daily training. The weight loss and muscle gain settings move the result down or up by 20%. It then shows a range 15% either side, because no single figure is exact. These are rule-of-thumb figures, not a medical guideline.
Is this carb calculator free?
Yes. It runs in your browser with no account and no payment. If you'd like somewhere to write down what you eat, Healthcount is a free food journal, and numbers are optional.

Thinking of cutting carbs hard?

Read why your body needs carbs and fat, and how CBT breaks the restrict-binge cycle, first.

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