🍞 Carbs 101
What is “carb intake,” and why does it matter?
Your carb intake is the amount of carbohydrates you eat each day — usually tracked in grams.
Carbs are your body’s easiest-to-use fuel, especially for higher-intensity exercise like lifting, sprinting,
interval training, and sports. They’re stored in muscles and liver as glycogen, and glycogen
helps you train harder, recover better, and feel less “flat” during a calorie deficit.
Carb needs aren’t one-size-fits-all. The right amount depends on your goals (cut, maintain, bulk),
your activity level, and how your body responds. Some people feel amazing on higher carbs.
Others prefer lower carbs as long as protein and overall calories are right.
What most people miss is the simplest truth: carbs are a lever. Once protein is steady
and fats are adequate, you can move carbs up or down to match your lifestyle and training.
When higher carbs tend to help
- Hard training (strength, sports, lots of volume)
- High step count / active job
- Refeed days during a cut
- People who struggle with sleep or mood when carbs are very low
When lower carbs can work well
- Lower activity lifestyles (or short-term appetite control)
- People who prefer higher fats (taste/satiety preference)
- Short dieting phases where simplicity matters more than performance
The “best” carb intake is the one you can stick to while keeping protein high, training consistent, and your weekly trend moving in the right direction.
🧮 Formula breakdown
How the calculator finds your carbs (grams)
This calculator uses straightforward macro math:
Calories = (Protein g × 4) + (Carbs g × 4) + (Fat g × 9).
If you choose a calorie target and decide your protein and fat targets, the remaining calories become carbs.
Step 1: Set calories
You can choose:
- Auto mode: estimate calories from your body stats and activity (BMR → TDEE → goal multiplier).
- Manual mode: enter your own calorie target (kcal/day).
In Auto mode, we estimate BMR with Mifflin–St Jeor and then estimate TDEE with an activity factor:
- Men: BMR = 10×kg + 6.25×cm − 5×age + 5
- Women: BMR = 10×kg + 6.25×cm − 5×age − 161
- TDEE: BMR × activityFactor
Then your goal changes calories:
maintain ≈ 100% TDEE, cut ≈ 85–90% TDEE, lean bulk ≈ 105–110% TDEE, refeed ≈ 100–105% TDEE.
Step 2: Set protein and fat
Defaults:
protein = 1.8 g/kg (supports muscle retention and satiety),
fat = 0.8 g/kg (supports hormones and food enjoyment).
You can override both, because preferences vary.
Step 3: Carbs are “what’s left”
Once calories, protein, and fat are set:
carbCalories = totalCalories − proteinCalories − fatCalories,
then carbs (g) = carbCalories / 4.
If your carb result looks surprisingly low or high, it’s usually because protein or fat are set very high.
That’s not “wrong” — it just means you’re prioritizing those macros, and carbs shrink accordingly.
Example
Suppose you choose 2,300 kcal/day. At 78 kg, protein 1.8 g/kg → 140 g (560 kcal). Fat 0.8 g/kg → 62 g (558 kcal).
Remaining calories: 2,300 − 560 − 558 = 1,182 kcal → carbs ≈ 296 g/day.