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Carbohydrate Calculator


Use this Carbohydrate Calculator to estimate daily carb needs based on your weight, activity level, and goal. Choose a method: percentage of calories or grams per kilogram.

Tip: If you know your total daily calories, choose the percentage method. If you prefer sport nutrition guidelines, use grams per kilogram.

Notes: For the percentage method, fill in both total daily calories and carb percentage. For the g/kg method, calories are optional and used only to show what percent of calories your carbs represent.

Use our Carbohydrate Calculator to pinpoint how many grams of carbs you need per day and per meal based on your weight, activity level, and fitness goals. Whether you prefer a percentage-of-calories approach or sport-nutrition guidelines (grams per kilogram), this tool turns confusing math into clear, actionable targets.

Why a Carbohydrate Calculator matters

Carbohydrates fuel your brain and working muscles. Getting the right amount can boost workout performance, stabilize energy, and support fat loss or muscle gain. Too few carbs can leave you dragging, while too many can overshoot your calorie needs. A calculator provides a personalized starting point so you can dial in your nutrition faster and with less guesswork.

Two evidence-based ways to set carb targets

1) Percentage of total calories

This method is simple: choose what percentage of your daily calories should come from carbohydrates. Common ranges are 40–60% for balanced diets, 20–35% for lower-carb approaches, and 55–65% for endurance-focused plans. Because each gram of carbohydrate contains 4 calories, you can convert a percentage directly into grams per day.

  • Balanced: 40–55% of calories from carbs
  • Lower carb: 20–35% of calories from carbs
  • Endurance/high volume: 55–65% of calories from carbs

Pros: easy, flexible, works with any calorie target. Cons: doesn’t directly account for training volume or body size.

2) Grams per kilogram of body weight (g/kg)

Widely used in sport nutrition, this method scales carbs to your body size and training load. Typical daily ranges:

  • Sedentary: ~2–3 g/kg
  • Light activity (1–3 hrs/week): ~3–5 g/kg
  • Moderate (3–5 hrs/week): ~5–7 g/kg
  • High (6–10 hrs/week): ~6–10 g/kg
  • Extreme (10+ hrs/week): ~8–12 g/kg

Within each range, you can bias low for fat loss, middle for maintenance, and high for muscle gain or heavy performance demands. Our Carbohydrate Calculator automates this choice and converts your selection into grams per day and per meal.

How to use the Carbohydrate Calculator

  1. Select a calculation method: percentage of calories or grams per kilogram.
  2. Enter your body weight and choose your unit (kg or lb).
  3. Pick your activity level and primary goal.
  4. If using the percentage method, enter your daily calories and desired carb percentage.
  5. Choose how many meals you typically eat each day to get per-meal targets.

The result section shows your daily carbohydrate target, carbs per meal, the assumed g/kg intensity, and how many calories those carbs represent. If you provide calories, you’ll also see the effective percentage of your intake.

Smart tips for applying your results

  • Distribute carbs around training: consume more before and after workouts to support performance and recovery.
  • Prefer minimally processed carb sources: fruit, vegetables, whole grains, legumes, potatoes, oats, and rice.
  • Combine carbs with protein and some fat to improve satiety and maintain steady energy.
  • Adjust weekly: if energy is low during training, increase carbs slightly; if fat loss stalls, trim carbs or overall calories.
  • Fiber matters: aim for at least 14 g of fiber per 1,000 kcal. The calculator reminds you of this general guideline.

Example scenarios

Endurance trainee: A 70 kg runner training 5 days per week could select the moderate to high activity category. At ~6 g/kg, that’s about 420 g carbs per day. Spread over 4 meals, this is roughly 105 g per meal, with extra emphasis around runs.

Fat loss: A 90 kg individual with light activity might choose 3 g/kg, about 270 g per day to start, then adjust downward if total calorie reduction is needed. Alternatively, at 2,200 kcal with 35% carbs, that’s 770 kcal from carbs, or ~193 g per day.

Frequently adjusted factors

As training volume, body weight, or goals change, your carb target should evolve. During deload weeks, shift to the lower end of your range. Building toward a race or heavy training block? Nudge toward the higher end. The Carbohydrate Calculator helps you make those updates quickly and consistently.

Bottom line

There’s no single perfect carbohydrate target for everyone, but there is a smart starting point for you. Use the Carbohydrate Calculator to translate science-backed guidelines into a personalized daily plan, test it for a week or two, and fine-tune based on performance, hunger, and results.


FAQs

How does the Carbohydrate Calculator decide my daily carb grams?

It uses either a percentage of your daily calories or sport-nutrition g/kg ranges adjusted for activity level and goal.

Which method should I pick in the Carbohydrate Calculator: percent or g/kg?

Use percent if you know your calories. Use g/kg if you want activity-scaled targets based on body weight.

Can the Carbohydrate Calculator show carbs per meal?

Yes. Enter meals per day and it will divide your daily carbs into simple per-meal targets.

Does the Carbohydrate Calculator work for low-carb diets?

Yes. Choose a lower percentage or select the g/kg method and pick a lower end of the activity range.

Will the Carbohydrate Calculator adjust for fat loss vs muscle gain?

Yes. Selecting your goal biases the recommendation lower for fat loss, middle for maintenance, and higher for muscle gain.

Do I need to enter calories in the Carbohydrate Calculator?

Only for the percentage method. The g/kg method works without calories and can still show your implied percent.

Is the Carbohydrate Calculator accurate for athletes?

It follows widely used g/kg ranges by activity. Fine-tune based on performance, recovery, and coach or clinician guidance.