CALCULATOR
Carbohydrate Calculator
Daily carbohydrate in grams once protein and fat are set, with lower carb and higher carb options.
Your carb target
—
Estimate based on the Mifflin-St Jeor equation. Adjust over 2-3 weeks based on real-world results. General guidance, not medical advice.
How carbohydrate targets are set
Carbohydrate is the macronutrient with the widest reasonable range, and the one with the least evidence for any single optimal intake. That is why this calculator sets it last: protein is fixed by bodyweight, fat is set with a health floor, and carbohydrate fills whatever calories remain.
This ordering is deliberate. Protein and fat both have minimums below which health or body composition suffers. Carbohydrate has no strict dietary requirement, because the body can produce glucose from other sources, but it is the preferred fuel for hard training and the easiest way to make a diet enjoyable and sustainable.
The practical consequence is that your carbohydrate number moves a lot depending on your calorie target and your chosen fat intake, and both of those can be right. Someone thriving on 150 g of carbs and someone thriving on 400 g may both be correct for their situation.
Where your carbohydrate number comes from
2. fat kcal = fat g x 9
3. carb kcal = total calories - protein kcal - fat kcal
4. carb grams = carb kcal / 4
Carbohydrate by diet style, 80 kg at 2,650 kcal
| Style | Fat share | Carbs | Percent of calories |
|---|---|---|---|
| Higher carb | 22% | 394 g | 59% |
| Balanced | 28% | 333 g | 50% |
| Lower carb | 35% | 256 g | 39% |
Carbohydrate needs by training type
| Training | g per kg per day | 80 kg example |
|---|---|---|
| Little or none | 2-3 g | 160-240 g |
| Moderate, about 1 hour daily | 5-7 g | 400-560 g |
| Endurance, 1-3 hours daily | 6-10 g | 480-800 g |
| Extreme, 4+ hours daily | 8-12 g | 640-960 g |
These are sports-nutrition guidelines for performance rather than general health, and the upper ranges only apply to genuinely high training volumes. Most people reading this sit in the first two rows, and the calculator output above will usually be lower because it is constrained by your calorie target.
Carbohydrate in common foods
| Food | Serving | Carbs | Fibre |
|---|---|---|---|
| White rice, cooked | 100 g | 28 g | 0.4 g |
| Oats, dry | 50 g | 30 g | 5 g |
| Potato, boiled | 200 g | 34 g | 4 g |
| Sweet potato, baked | 200 g | 41 g | 6 g |
| Pasta, cooked | 100 g | 25 g | 1.8 g |
| Banana | 1 medium | 27 g | 3 g |
| Bread, wholemeal | 1 slice | 12 g | 2 g |
| Lentils, cooked | 100 g | 20 g | 8 g |
Fibre, the part most people miss
Fibre is a carbohydrate your body does not digest, and most adults fall well short of the commonly recommended 25 to 30 grams a day. It supports digestive health, slows glucose absorption and contributes substantially to feeling full, which makes it disproportionately useful when dieting. Prioritising whole grains, legumes, vegetables and fruit within your carbohydrate allowance is a better lever than obsessing over the total.
Frequently asked questions
How many carbs should I eat per day?
Are low carb diets better for fat loss?
Do I need carbs to build muscle?
What is the minimum carbohydrate intake?
Sources
- Institute of Medicine. Dietary Reference Intakes: Acceptable Macronutrient Distribution Ranges, 2005.
- Burke LM et al. Carbohydrates for training and competition. Journal of Sports Sciences, 2011.
- Reynolds A et al. Carbohydrate quality and human health. The Lancet, 2019.
- National Institutes of Health, Office of Dietary Supplements. Nutrient fact sheets. ods.od.nih.gov
- NHS. Nutrition and health guidance. nhs.uk
- US Departments of Agriculture and Health and Human Services. Dietary Guidelines for Americans, 2025-2030. dietaryguidelines.gov
More tools: all calculators · Full Plan · Recomp · Body fat · Macros · Cheapest whey per 20 g
General information, not medical advice. Consult a qualified professional before changing your diet, especially with a medical condition.