Carb CalculatorHow Many Carbs Should I Eat a Day?
Find your daily carbohydrate target in grams, either for a diet goal (keto to standard) or for athletic training load, with per-meal amounts, food equivalents and workout fuelling windows.
Built & medically reviewed by Manzoor Ahmad, Pharmacist & Calculator Developer · Updated
Based on the Dietary Guidelines AMDR, the 130 g RDA and the ACSM nutrition and athletic performance position stand.
How many carbs should you eat a day?
Health guidelines recommend getting 45–65% of calories from carbs, which is 225–325 g on a 2,000-calorie diet, with a minimum of 130 g. Low-carb diets use 50–130 g and keto 20–50 g. Athletes base carbs on body weight instead: 5–7 g/kg for about an hour of training a day, and up to 10–12 g/kg for very high volumes.
Your carbs
feet · inches
Range 145–180 g · 650 kcal of your 1,625
What that looks like in food
Workout fuelling
How many carbs per day? Ranges by goal
| Goal / approach | Carbs per day | % of calories | Source |
|---|---|---|---|
| Keto | 20–50 g | ≈ 5–10% | Clinical ketogenic protocols |
| Low carb | 50–130 g | ≈ 10–26% | ADA nutrition consensus |
| Minimum for brain glucose (RDA) | 130 g | — | National Academies |
| Standard healthy diet | 225–325 g (2,000 kcal) | 45–65% | Dietary Guidelines AMDR |
| Moderate training (1 h/day) | 5–7 g/kg | — | ACSM / IOC |
| Endurance (1–3 h/day) | 6–10 g/kg | — | ACSM / IOC |
Two ways we calculate carbs
Athletes are given carbs per kilogram rather than a percentage, because fuel needs scale with training volume, not with calories.
143 lb (65 kg) woman, two scenarios
- Diet, losing weight, moderate carb: 1,625 kcal × 40% ÷ 4 = 163 g a day (about 54 g per meal).
- Athlete, 1 hour a day of training: 65 × 5–7 g = 325–455 g a day.
- Same person, same day: up to 3× the carbs, because training fuel needs are so different.
Carbs, diabetes and medication timing
If you use mealtime insulin, your carb grams drive your dose. Most people use an insulin-to-carb ratio, for example 1 unit per 10–15 g, set by their diabetes team. Never change your ratio based on a general calculator. If you take sulfonylureas (gliclazide, glimepiride), skipping carbs at a meal can cause hypoglycaemia, so keep your carb intake consistent from day to day.
Carb counts on labels include fibre in the US but not in the UK and EU. Check which you’re reading before you dose insulin or track net carbs.
Related calculators
Carb calculator FAQs
The Dietary Guidelines recommend that 45–65% of calories come from carbohydrates, which is 225–325 g on a 2,000-calorie diet. The RDA minimum is 130 g a day. Low-carb diets use 50–130 g and keto diets 20–50 g.
Total calories matter more than the carb amount itself. Many people find 100–150 g a day (about 25–40% of calories) a comfortable middle ground for weight loss, with protein kept high.
Athletes need 3–5 g/kg for light training, 5–7 g/kg for about an hour a day, 6–10 g/kg for 1–3 hours of endurance training, and 8–12 g/kg for extreme daily volumes, according to ACSM and IOC guidelines.
Low carb is usually defined as under 130 g a day (less than 26% of calories). Very low carb or ketogenic diets are 20–50 g a day.
No. Whole-food carbohydrates such as whole grains, legumes, fruit and vegetables are linked to lower risk of heart disease, type 2 diabetes and bowel cancer. The quality of carbs matters more than the amount: limit refined grains and added sugars.
There’s no single target. The American Diabetes Association recommends individualised plans, and low-carb eating patterns have good evidence for improving blood sugar. Work with your diabetes team, especially if you use insulin or sulfonylureas.
For most people on a moderate-carb diet, 30–60 g per meal works well. People with diabetes are often advised to aim for 30–45 g (women) or 45–60 g (men) per meal, adjusted with their care team.
Manzoor Ahmad
Pharmacist · Supplement & Nutrition Writer (9+ yrs) · Calculator Developer (13+ yrs)
I’m a practising pharmacist and DexoCalc’s developer. People on insulin and sulfonylureas often ask me about carbs at the pharmacy, so this tool separates diet goals from athletic fuelling. It also warns where carb changes interact with diabetes medicines.
References
- Thomas DT, Erdman KA, Burke LM. ACSM Joint Position Statement: Nutrition and Athletic Performance. Med Sci Sports Exerc. 2016;48(3):543–568. PubMed
- Institute of Medicine. DRIs for Energy, Carbohydrate, Fiber, Fat…
- Evert AB, et al. Nutrition therapy for adults with diabetes or prediabetes: a consensus report. Diabetes Care. 2019;42(5):731–754. PubMed
- Reynolds A, et al. Carbohydrate quality and human health. Lancet. 2019;393(10170):434–445. PubMed
- USDA. Dietary Guidelines for Americans.
Medical disclaimer: Carb targets are general estimates and are not medical advice. If you have diabetes, especially if you use insulin or sulfonylureas, follow the carb plan agreed with your care team.