How to Calculate Your Macros: A Beginner's Guide
Learn how to calculate your optimal macronutrient split for muscle gain, fat loss, or maintenance. We break down the science into simple, actionable steps.
ShredSheet Team
Author
Whether you’re trying to build muscle, lose fat, or just eat healthier, understanding your macros is the single most impactful thing you can do. Here’s how to get started.
What Are Macros?
Macronutrients – or “macros” – are the three main categories of nutrients your body needs in large amounts:
- Protein – builds and repairs muscle tissue (4 calories per gram)
- Carbohydrates – your body’s primary energy source (4 calories per gram)
- Fat – essential for hormones, brain function, and nutrient absorption (9 calories per gram)
Every food you eat is a combination of these three. Tracking them gives you far more control over your body composition than just counting calories alone.
Step 1: Calculate Your TDEE
Your Total Daily Energy Expenditure (TDEE) is how many calories you burn in a day. It’s based on two things:
- BMR (Basal Metabolic Rate) – calories burned just existing
- Activity multiplier – how active you are
ShredSheet uses the Mifflin-St Jeor equation, which is the most accurate for most people:
Men: BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age) + 5
Women: BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age) - 161
Then multiply by your activity level:
- Sedentary (desk job): × 1.2
- Lightly active (1-3 days/week): × 1.375
- Moderately active (3-5 days/week): × 1.55
- Very active (6-7 days/week): × 1.725
Step 2: Set Your Calorie Target
Once you know your TDEE, adjust based on your goal:
- Fat loss: TDEE minus 300-500 calories
- Muscle gain: TDEE plus 200-300 calories
- Maintenance: Stay at TDEE
Don’t go too aggressive. A moderate deficit preserves muscle and is far more sustainable than crash dieting.
Step 3: Split Your Macros
A solid starting point for most people:
| Goal | Protein | Fat | Carbs |
|---|---|---|---|
| Fat Loss | 2.0g/kg | 0.8g/kg | Remaining calories |
| Muscle Gain | 1.8g/kg | 1.0g/kg | Remaining calories |
| Maintenance | 1.6g/kg | 1.0g/kg | Remaining calories |
Example: An 80kg male eating 2,400 calories for fat loss:
- Protein: 160g (640 cal)
- Fat: 64g (576 cal)
- Carbs: 296g (1,184 cal)
Step 4: Track Consistently
The best macro split means nothing if you don’t track it. That’s where ShredSheet comes in – scan barcodes, search our database of thousands of foods, and see your daily macro breakdown at a glance.
The key is consistency, not perfection. Hit your targets within 5-10% most days, and the results will come.
Common Mistakes to Avoid
- Setting protein too low – Most people undereat protein. It’s the most important macro for body composition.
- Cutting fat too much – Your hormones need dietary fat. Never go below 0.6g/kg.
- Ignoring fiber – Aim for 25-35g of fiber daily, regardless of your macro split.
- Obsessing over meal timing – When you eat matters far less than what and how much you eat.
Get Started
The easiest way to calculate and track your macros is to download ShredSheet. The app calculates your optimal targets automatically based on your body data and goals – no spreadsheets required.