Carbohydrate Calculator
Use this calculator to determine your daily carbohydrate needs based on your age, gender, height, weight, and activity level. Perfect for diet planning and weight management.
Your Daily Carbohydrate Needs
| Macronutrient | Grams per day | Calories per day |
|---|---|---|
| Carbohydrates | 0 | 0 |
| Protein (20%) | 0 | 0 |
| Fat (30%) | 0 | 0 |
About the Carbohydrate Calculator
The carbohydrate calculator helps you determine your daily carbohydrate needs based on your personal factors including age, gender, height, weight, and activity level. Carbohydrates are your body's main source of energy and should make up 45-65% of your total daily calories according to dietary guidelines.
How Carbohydrate Needs Are Calculated
The calculator uses the following steps to determine your carbohydrate needs:
- Calculate Basal Metabolic Rate (BMR): This is the number of calories your body needs at rest. We use either the Mifflin-St Jeor equation (recommended), the Harris-Benedict equation, or the Katch-McArdle formula (if body fat percentage is provided).
- Adjust for Activity Level: Your BMR is multiplied by an activity factor to estimate your total daily energy expenditure (TDEE).
- Determine Carbohydrate Intake: Your TDEE is multiplied by your selected carbohydrate ratio (default 50%) to determine calories from carbs, which is then converted to grams (4 calories per gram of carbohydrate).
BMR Estimation Formulas
The calculator offers three methods for estimating your Basal Metabolic Rate:
- Mifflin-St Jeor Equation (recommended): Considered the most accurate for most people.
- Men: BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age(y) + 5
- Women: BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age(y) - 161
- Revised Harris-Benedict Equation: Older but still widely used formula.
- Men: BMR = 13.397 × weight(kg) + 4.799 × height(cm) - 5.677 × age(y) + 88.362
- Women: BMR = 9.247 × weight(kg) + 3.098 × height(cm) - 4.330 × age(y) + 447.593
- Katch-McArdle Formula: Requires body fat percentage but can be more accurate for lean individuals.
- BMR = 370 + 21.6 × lean mass(kg)
- Lean mass = weight × (100 - body fat %) / 100
Activity Level Multipliers
Your BMR is multiplied by an activity factor to estimate your total daily calorie needs:
| Activity Level | Description | Multiplier |
|---|---|---|
| Sedentary | Little or no exercise | 1.2 |
| Lightly Active | Exercise 1-3 times/week | 1.375 |
| Moderately Active | Exercise 4-5 times/week | 1.55 |
| Very Active | Daily exercise or intense exercise 3-4 times/week | 1.725 |
| Extra Active | Very intense exercise daily, or physical job | 1.9-2.0 |
Why Carbohydrates Matter
Carbohydrates are essential for:
- Providing energy for your brain and muscles
- Supporting physical activity and exercise performance
- Maintaining proper digestive function (fiber is a type of carbohydrate)
- Supporting metabolic processes and hormone regulation
Adjusting Carbohydrate Intake
Your carbohydrate needs may vary based on:
- Activity Level: More active individuals typically need more carbohydrates
- Health Goals: Weight loss, maintenance, or muscle gain may require different carb intakes
- Health Conditions: Diabetes or metabolic conditions may require carb monitoring
- Personal Preference: Some people feel better with higher or lower carb diets