How do I calculate my macros from calories?

Formula (Atwater factors): Protein grams = (calories × protein%) ÷ 4 Fat grams = (calories × fat%) ÷ 9 Carb grams = (calories × carb%) ÷ 4 Example: 2,000 kcal with 30% protein / 30% fat / 40% carbs: Protein = 2000 × 0.30 ÷ 4 = 150g Fat = 2000 × 0.30 ÷ 9 = 67g Carbs = 2000 × 0.40 ÷ 4 = 200g Why different divisors? 1g protein = 4 kcal 1g fat = 9 kcal (most calorie-dense macro) 1g carbs = 4 kcal Fat has more than double the calories per gram, which is why a 30% fat diet still means fewer grams than 30% protein at the same calorie level.

What is the best macro split for weight loss?

For weight loss, High Protein splits work best for most people: Protein: 30–35% Fat: 25–30% Carbs: 35–40% At 1,800 kcal: - Protein: 135–158g - Fat: 50–60g - Carbs: 158–180g Why high protein for weight loss: 1. Most satiating macro — reduces hunger and calorie intake naturally 2. Preserves muscle mass during a calorie deficit 3. Highest thermic effect — protein uses 20–30% of its own calories in digestion vs 5–10% for carbs and 0–3% for fat 4. Prevents the metabolic slowdown that comes with muscle loss Minimum protein for weight loss: 1.6g per kg body weight (or ~30% of calories, whichever is higher). Low carb and keto are effective for some people but have no metabolic advantage over balanced diets when protein and calories are matched.

What macros should I eat for muscle gain?

For muscle gain (lean bulk): Protein: 30–40% Fat: 20–30% Carbs: 35–50% At 2,500 kcal (lean bulk for ~80kg person): Protein: 188–250g Fat: 56–83g Carbs: 219–313g Key principles: 1. Protein: aim for 1.6–2.2g per kg body weight. Higher protein is not more effective beyond ~2.2g/kg for most people. 2. Carbs are your friend for muscle gain — they fuel training, spare protein from being used as energy, and support recovery via insulin and glycogen. 3. Fat supports hormone production (especially testosterone). Don't go below 20% fat. 4. Calorie surplus: 250–500 kcal above TDEE for lean gains (minimises fat gain) The Bodybuilding preset (40/20/40) maximises protein while keeping fat moderate and carbs high enough to fuel training.

What is the keto macro split?

The ketogenic diet uses a very high fat, very low carb split: Protein: 20–25% Fat: 65–75% Carbs: 5–10% At 2,000 kcal: Protein: 100–125g Fat: 144–167g Carbs: 25–50g The goal: restrict carbs to below 20–50g net carbs/day to force the liver to produce ketones from fat — shifting the body's primary fuel source from glucose to ketones. Net carbs = Total carbs − Dietary fiber (fiber isn't absorbed) When does keto work: - Drug-resistant epilepsy (strongest clinical evidence) - Type 2 diabetes management (reduces blood sugar dramatically) - Rapid fat loss (eliminates glycogen and water weight quickly) - Carbohydrate intolerance / metabolic syndrome Keto downsides: difficult to maintain long-term, limits food variety, may reduce athletic performance (carbs are the most efficient fuel for high-intensity exercise), requires electrolyte supplementation.

How many grams of protein do I need per day?

Protein needs by goal: Sedentary (minimum): 0.8g per kg body weight Active / recreational: 1.2–1.6g per kg Resistance training: 1.6–2.2g per kg Weight loss (preserve muscle): 1.8–2.4g per kg Elite athletes: 2.0–2.5g per kg For a 70kg person: - Sedentary minimum: 56g/day - Active: 84–112g/day - Building muscle: 112–154g/day - Weight loss: 126–168g/day Distribution matters: - Aim for 20–40g protein per meal - The body can use about 40g protein per meal efficiently for muscle protein synthesis - Spreading protein across 3–4 meals outperforms one large protein dose Protein quality: animal proteins (complete amino acid profile) are more efficient than plant proteins. Vegans/vegetarians need 10–20% more total protein to account for lower bioavailability.

FOOD MACROS CALCULATOR

Calculate your daily macro targets in grams from a calorie goal, or find total calories from your macro grams. Two modes: Calories to Macros (enter target calories and split percentage, get protein/fat/carbs in grams) and Macros to Calories (enter grams, get total calories and percentages). 8 preset...

MACRO CALCULATOR

Daily Calorie Target

kcal

Macro Split Preset

Custom Split (%)100% total ✓

Protein

25%

Fat

30%

Carbs

45%

MACRO TARGETS

PROTEIN

125g

FAT

67g

CARBS

225g

MACRO BREAKDOWN

Protein

125g (25%)

Fat

67g (30%)

Carbs

225g (45%)

PROTEIN

125g

500 kcal

25%

FAT

67g

600 kcal

30%

CARBS

225g

900 kcal

45%

ALL PRESETS AT 2000 KCAL

BalancedP25/F30/C45125g67g225g

High ProteinP35/F25/C40175g56g200g

Low CarbP30/F40/C30150g89g150g

KetoP25/F70/C5125g156g25g

Low FatP30/F20/C50150g44g250g

BodybuildingP40/F20/C40200g44g200g

EnduranceP20/F25/C55100g56g275g

Created with❤️byeaglecalculator.com

HOW TO USE

1
Choose your mode: Calories → Macros (enter a calorie target, get grams) or Macros → Calories (enter grams, get total calories and percentages). For most people, start with Calories → Macros: enter your daily calorie target (use our Daily Calorie Needs Calculator if you don't know it).
2
Select a macro split preset: Balanced (25/30/45), High Protein (35/25/40), Low Carb (30/40/30), Keto (25/70/5), Low Fat (30/20/50), Bodybuilding (40/20/40), Endurance (20/25/55). Or use Custom and adjust the protein, fat, and carbs sliders — the total must equal 100%. The All Presets comparison table on the right shows grams for all splits at once.
3
The macro donut chart shows your split visually with grams, kcal from each macro, and percentage. Use the reverse mode (Macros → Calories) to check if an existing macro target hits your calorie goal — enter your gram targets and see the total and percentage breakdown instantly.

MACRO SPLIT REFERENCE — ALL PRESETS

Split	%	1,500 kcal	1,800 kcal	2,000 kcal	2,200 kcal	2,500 kcal	Best for
Balanced	P25/F30/C45	P94/F50/C169g	P113/F60/C203g	P125/F67/C225g	P138/F73/C248g	P156/F83/C281g	General population, weight maintenance
High Protein	P35/F25/C40	P131/F42/C150g	P158/F50/C180g	P175/F56/C200g	P193/F61/C220g	P219/F69/C250g	Weight loss with muscle preservation
Low Carb	P30/F40/C30	P113/F67/C113g	P135/F80/C135g	P150/F89/C150g	P165/F98/C165g	P188/F111/C188g	Insulin resistance, steady energy
Keto	P25/F70/C5	P94/F117/C19g	P113/F140/C23g	P125/F156/C25g	P138/F171/C28g	P156/F194/C31g	Epilepsy, rapid fat loss, metabolic reset
Low Fat	P30/F20/C50	P113/F33/C188g	P135/F40/C225g	P150/F44/C250g	P165/F49/C275g	P188/F56/C313g	Heart health, very active individuals
Bodybuilding	P40/F20/C40	P150/F33/C150g	P180/F40/C180g	P200/F44/C200g	P220/F49/C220g	P250/F56/C250g	Maximum hypertrophy, strength athletes
Endurance	P20/F25/C55	P75/F42/C206g	P90/F50/C248g	P100/F56/C275g	P110/F61/C303g	P125/F69/C344g	Marathon, cycling, triathlon

Values in grams (g). Formula: Protein = kcal×%÷4 · Fat = kcal×%÷9 · Carbs = kcal×%÷4

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Food Macros Calculator · Protein = kcal×%÷4 · Fat = kcal×%÷9 · Carbs = kcal×%÷4 · Atwater factors · Estimates only — individual needs vary