Carb Calculator - Calculate Your Daily Carbohydrate Needs
Calculate your optimal daily carbohydrate intake based on your age, sex, activity level, and goals. Get carb targets for weight loss, maintenance, or muscle gain.
Personal Details
How to Use This Calculator
This tool estimates your daily carbohydrate needs by starting with your Basal Metabolic Rate (BMR) and layering in your activity level plus any goal adjustment. Switch between metric and imperial units, pick your biological sex, and fine-tune the activity factor and goal to reflect your lifestyle.
Why use this calculator
- Built on the science-backed Mifflin-St Jeor equation for BMR.
- Totals daily energy expenditure (TDEE) using PAL multipliers that cover sedentary to extra active.
- Applies goal-based calorie adjustments (loss, maintenance, or gain) before calculating macros.
- Shows balanced, low-carb, and high-carb plans for comparison.
- Downloads a CSV of every plan for meal planning or sharing with your coach.
Methodology
The calculator follows four steps: (1) compute BMR with the Mifflin-St Jeor equation, (2) multiply by your selected activity level to estimate TDEE, (3) add or subtract the goal adjustment (e.g., −500 kcal for standard weight loss), and (4) divide the resulting goal calories by the macro percentages to get grams for carbohydrates, protein, and fat.
Every calculation uses consistent rounding and safe-number handling so you never see NaN or Infinity in the UI.
Example scenario
For Alex, a 30-year-old male who is 180 cm tall, weighs 80 kg, is moderately active (PAL 1.55), and wants to maintain his weight, the calculator does the following:
- Calculate BMR (Male): $BMR = (10 × 80) + (6.25 × 180) - (5 × 30) + 5 = 1780 calories.
- Calculate TDEE: Multiply 1780 by 1.55 = 2759 calories.
- Apply goal: Maintenance adds 0, so goal calories remain 2759.
- Build Balanced plan: 40% carbs, 30% protein, 30% fat → carbs = (2759 × 0.40) / 4 ≈ 276 g.
Frequently Asked Questions
Why use the Mifflin-St Jeor equation?
It is widely regarded as the most accurate formula for estimating resting energy expenditure in healthy adults, often outperforming older equations.
What is the difference between BMR and TDEE?
BMR is the energy your body needs at rest. TDEE adds the energy burned from daily movement, exercise, and digestion.
How accurate is this calculator?
It provides a high-quality estimate. Adjust the goal or PAL if real-world progress differs due to genetics, body composition, or recovery.
How many carbs should I eat to lose weight?
To lose weight, a deficit such as −500 calories per day is applied before the macro split. Balanced or low-carb plans help with satiety on the reduced calories.
What are 'net carbs' and does this calculator track them?
This calculator reports total carbohydrates. Subtract your daily fiber target (25–30 g) to estimate net carbs if needed.
Why is protein important when calculating carbs?
Protein supports muscle repair and satiety, especially in a deficit. A consistent macro split ensures carbs fit within a balanced intake.
Is a low-carb or high-carb plan better?
High-carb plans suit endurance athletes, low-carb suits weight loss or blood-sugar control, and balanced splits are sustainable for most people.
Tool developed by Ugo Candido.
Health and nutrition content verified by the CalcDomain Editorial Board, including Registered Dietitians (RDN).
Last accuracy review: .