Calculator Inputs
Example Data Table
| Profile | Weight | Calories | Protein | Fat | Carbs | Carbs/kg |
|---|---|---|---|---|---|---|
| Lean male lifter, 4 days | 70 kg | 2,850 kcal | 140 g | 56 g | 447 g | 6.39 |
| Female intermediate, 5 days | 60 kg | 2,350 kcal | 120 g | 48 g | 359 g | 5.98 |
| Heavy bulk athlete, 6 days | 90 kg | 3,650 kcal | 180 g | 81 g | 550 g | 6.11 |
| Slow bulk office worker, 3 days | 82 kg | 2,950 kcal | 164 g | 66 g | 409 g | 4.99 |
These examples illustrate how calories left after protein and fat become your daily carbohydrate budget.
Formula Used
1) Basal metabolic rate
If body fat is available and valid, the calculator uses Katch-McArdle:
BMR = 370 + (21.6 × lean body mass in kg)
Otherwise it uses Mifflin-St Jeor:
BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) + sex constant
2) Total daily energy expenditure
TDEE = BMR × activity factor
3) Bulking calories
Target calories = TDEE + calorie surplus
4) Protein and fat allocation
Protein grams = body weight × protein g/kgFat grams = body weight × fat g/kg
5) Carb intake for bulking
Carb calories = target calories − (protein grams × 4) − (fat grams × 9)Carb grams = carb calories ÷ 4
6) Carb cycling split
Training day carbs = base carbs × (1 + boost %)Rest day carbs = remaining weekly carbs ÷ rest days
How to Use This Calculator
- Choose metric or imperial units, then enter your age, sex, body weight, and height.
- Add body fat if you know it. This improves BMR accuracy through lean mass estimation.
- Select your activity factor and weekly training frequency.
- Pick a bulking pace or enter a custom calorie surplus.
- Set your protein and fat targets in grams per kilogram.
- Define meal frequency plus pre-workout and post-workout carb shares.
- Press Calculate Carb Intake to show results above the form.
- Review carb totals, training/rest-day targets, meal distribution, and the plotted graph.
- Use the export buttons to download your result table as CSV or PDF.
FAQs
1. Why are carbs usually high during a bulk?
Carbohydrates refill muscle glycogen, support training volume, and spare protein. During a bulk, they also help raise calories efficiently without pushing dietary fat too high.
2. Should I change carbs on rest days?
Many athletes keep carbs slightly lower on rest days and slightly higher on training days. This calculator estimates both while keeping your weekly intake aligned with the chosen base target.
3. What if I do not know my body fat percentage?
Leave body fat blank or enter zero. The calculator then uses a widely accepted height, weight, age, and sex equation instead of lean-mass-based estimation.
4. Is a larger calorie surplus always better for muscle gain?
Not usually. Larger surpluses can increase body fat faster than muscle. A moderate or lean surplus is often easier to manage while still supporting progressive training.
5. How much protein and fat should I set?
Many bulking plans work well around 1.6–2.2 g/kg protein and 0.6–1.0 g/kg fat. Your remaining calories can then be assigned to carbohydrates.
6. Are pre-workout and post-workout carbs necessary?
They are not mandatory, but they are often useful. Placing carbs near training can improve session energy, recovery, and comfort when total daily intake is high.
7. What does carbs per kilogram tell me?
It helps compare your intake with sports nutrition ranges. This is especially useful when body size differs across athletes or when evaluating training-season adjustments.
8. Can I use this for cutting or maintenance?
Yes, but change the surplus logic. For maintenance use zero surplus. For cutting, use a deficit and keep protein high while recalculating carb intake from remaining calories.