About the Carbohydrate Calculator
Carbohydrates are one of the three macronutrients that supply energy, giving 4 calories per gram. How many you need depends on your total calories and on how you prefer to eat. This carbohydrate calculator turns a share of your daily calories into grams. Choose from very low, low, moderate, standard or high carb ranges, and enter your daily calories, or let the tool estimate them from your sex, age, weight, height and activity with the Mifflin-St Jeor equation. It returns a range in grams, the middle of the range, a per-meal figure and a fibre target of 14 grams per 1,000 calories.
Updated October 2026
How to use the Carbohydrate Calculator
- 1Choose whether you know your daily calories or want to estimate them.
- 2Enter your calories, or your sex, age, weight, height and activity.
- 3Choose your carb target from very low to high.
- 4Read the daily range in grams.
- 5Use the per-meal figure and the fibre target to plan your meals.
Worked example
A woman who is 35, 70 kg, 170 cm and moderately active needs about 2,210 calories a day. With a balanced 45 to 65 percent target, she should eat roughly 249 to 359 grams of carbohydrate daily, about 304 in the middle, which is around 101 grams at each of three meals. Her fibre target is at least 31 grams. If she prefers a low-carb plan at 10 to 25 percent, the range falls to 55 to 138 grams.
Planning your meals
- Spread carbs across the day, with more around exercise.
- Choose high-fibre sources such as oats, beans and vegetables.
- Pair carbs with protein and fat for a slower rise in blood sugar.
- Read labels: the carbs figure includes sugars and starches.
- Adjust portions for how you feel and your results.
Health notes
People with diabetes, kidney disease or a history of eating disorders, and anyone who is pregnant, should follow advice from their healthcare team rather than a general calculator. Sudden big cuts to carbohydrates can cause tiredness, headaches and dizziness for a few days, so change gradually and drink enough fluid.
Related tools
The Macro Calculator splits all three macronutrients, the Fat Intake Calculator and Protein Calculator work out the other two, the TDEE Calculator gives your daily calorie burn and the Calorie Calculator helps you set a goal.
Features
- Carb range in grams per day
- Five eating styles from keto-style to high-carb
- Optional calorie estimate
- Per-meal guide
- Fibre target
- Works in metric units
Frequently asked questions
How many carbs should I eat a day?
Official guidance for most adults is 45 to 65 percent of calories from carbohydrates. On 2,200 calories that is 248 to 358 grams a day. Low-carb plans use less, and endurance athletes may eat more.
How do I convert calories to grams of carbs?
Take the share of calories from carbs and divide by 4. For 2,200 calories at 50 percent, 1,100 calories come from carbs, which is 275 grams.
What is a low-carb diet?
Definitions vary. Many programmes use 10 to 25 percent of calories from carbohydrate, or roughly 50 to 130 grams a day, and ketogenic plans go below about 50 grams. These diets may not suit everyone, so talk to a professional first.
Should I count net carbs?
Net carbs are total carbs minus fibre, and sometimes sugar alcohols. Some plans count them, but this calculator uses total carbohydrates, which is the figure on most food labels.
Does the type of carb matter?
Yes. Whole grains, beans, fruit, vegetables and dairy bring fibre and nutrients, while sugary drinks and refined snacks bring calories with little else. Most health bodies advise keeping added sugar under 10 percent of calories.
How accurate is the calorie estimate?
The Mifflin-St Jeor equation is a standard estimate that can be off by 10 percent or more for an individual. Adjust it using how your weight changes over a few weeks.