What Are Macros?
Macronutrients — macros — are the three nutrients your body uses for energy: protein, carbohydrates, and fat. Every calorie you eat comes from one of them. Tracking macros means controlling not just how much you eat, but what you eat, which makes it far more precise than calorie counting alone.
Those numbers are what the calculation is built on. Fat is more than twice as calorie-dense as protein or carbs — which is why macro ratios matter more than just picking a calorie target.
Step 1: Find Your TDEE
TDEE — Total Daily Energy Expenditure — is the number of calories your body burns in a day, including activity. It's the baseline everything else is built on. If you eat at your TDEE, your weight stays roughly the same.
TDEE is calculated from your basal metabolic rate (BMR) multiplied by an activity factor. The formula involves your height, weight, age, and how often you exercise. Rather than doing it by hand, use the TDEE calculator to get your number before coming back to set your macros.
Step 2: Set Your Calorie Target
Once you have your TDEE, adjust it based on your goal.
| Goal | Calorie target | Notes |
|---|---|---|
| Lose fat | TDEE − 300 to 500 cal | Moderate deficit preserves muscle better than aggressive cuts |
| Maintain | TDEE | Eat at maintenance to hold current weight and body composition |
| Build muscle | TDEE + 250 to 500 cal | Small surplus minimises fat gain while supporting growth |
Step 3: Set Your Protein Target First
Protein is always calculated first because it's non-negotiable — it preserves muscle during a cut and supports growth during a bulk. The standard range is 0.7–1 g per lb of bodyweight per day.
Use the higher end (1 g/lb) if you're in a calorie deficit or training hard. Use the lower end (0.7 g/lb) if you're at maintenance or a modest surplus.
Step 4: Divide Fat and Carbs
With your protein calories locked in, subtract them from your total calorie target. The remaining calories are split between fat and carbs.
Fat: Set fat at 25–35% of your total daily calories. Fat supports hormones, joint health, and fat-soluble vitamins — don't go lower than 20% for extended periods.
Carbs: Carbs fill whatever is left after protein and fat are set. They fuel training and top up glycogen — the closer you are to maintenance or a surplus, the more room there is for carbs.
Worked Example
A 150 lb person with a TDEE of 2,100 calories wants to lose fat.
| Step | Calculation | Result |
|---|---|---|
| Calorie target (deficit) | 2,100 − 400 | 1,700 cal/day |
| Protein | 150 lb × 0.85 g/lb | 128 g → 512 cal |
| Fat (30% of total) | 1,700 × 0.30 ÷ 9 | 57 g → 510 cal |
| Carbs (remainder) | (1,700 − 512 − 510) ÷ 4 | 170 g → 678 cal |
Why Fat Has More Than Twice the Calories
This is the single most useful thing to understand when reading a nutrition label. Gram for gram, fat delivers more than double the energy of protein or carbs — which is why small changes in fat intake have a bigger impact on total calories than equivalent changes in protein or carbs.
Common Macro Split Presets
These are starting points, not rules. Adjust based on how you feel, how you perform, and how your body responds over 3–4 weeks.
| Approach | Protein | Carbs | Fat | Best for |
|---|---|---|---|---|
| Balanced | 30% | 40% | 30% | General fitness, maintenance |
| High-protein | 40% | 35% | 25% | Fat loss, muscle retention |
| Low-carb | 35% | 20% | 45% | Fat loss, insulin sensitivity |
| Keto | 25% | <5% | 70%+ | Ketosis, specific therapeutic use |
| Performance / bulk | 25% | 50% | 25% | Muscle building, high training volume |
Tips for Hitting Your Macros Consistently
- Track for two weeks before adjusting. One week of data is noise. Two weeks shows a pattern. Don't change targets based on a single bad day.
- Hit protein first, every day. Protein is the hardest macro to hit and the most important. Plan your protein sources first, then build the rest of the meal around them.
- Weigh food raw. Cooked weights vary significantly — chicken loses up to 25% of its weight when cooked. Weighing raw keeps your numbers consistent.
- Don't obsess over hitting exact numbers. Being within 5g on each macro is close enough. Precision matters less than consistency over weeks and months.
- Adjust every 4–6 weeks. As your weight changes, your TDEE changes. Recalculate your targets every month or whenever your progress stalls for more than two weeks.
Frequently Asked Questions
Do I need to count macros, or is just counting calories enough?
Calories in vs. calories out drives weight change, so calorie counting alone works for that goal. But macros matter for body composition — two people eating the same calories can end up with very different amounts of muscle vs. fat depending on their protein intake. If your goal is to look and perform better, not just weigh less, tracking macros gives you the control that calorie counting alone doesn't.
How much protein do I actually need per day?
For most people who exercise, 0.7–1 g per lb of bodyweight per day is the effective range. The higher end applies if you're in a calorie deficit, training frequently, or over 40 (older adults need more protein to stimulate the same muscle protein synthesis response). Sedentary adults need less — around 0.36 g/lb — but this is a floor for health, not a target for fitness.
What happens if I go over my fat macro?
Going slightly over fat won't derail your progress — what matters is your total calorie intake. However, because fat has 9 cal/g, small overages in grams add up to large calorie overages fast. If you regularly overshoot fat and undereat carbs, you're likely eating more total calories than you think, even if protein looks right.
Can I eat any carbs I want as long as I hit my macro number?
Technically, hitting the gram target matters more than the source for body composition. In practice, 200g of carbs from oats, fruit, and rice will leave you fuller, more energised, and performing better than 200g from biscuits and juice. The number sets the target; food quality determines how well you actually feel and recover.
How do I calculate macros for a day where I don't train?
Use a lower TDEE multiplier on rest days — typically "sedentary" or "lightly active" rather than your training-day activity level. Some people use the same targets every day for simplicity; others cycle — higher carbs on training days, lower carbs on rest days with fat slightly higher. Both approaches work. Consistency matters more than which system you pick.