Macros (macronutrients) are the three main nutrients your body needs in large amounts: protein, carbohydrates, and fat. Each provides energy (calories/kilojoules) and plays different roles in your body.

How much protein do I need?

For weight loss, aim for 1.6-2.2g of protein per kg of body weight to preserve muscle mass. For maintenance, 1.2-1.6g/kg is sufficient. For muscle gain, target 1.6-2.2g/kg. This calculator shows your protein intake in g/kg so you can check your targets at a glance.

Should I track macros or just calories?

Tracking macros gives you more control over body composition than tracking calories alone. Two diets with the same calories but different macro splits can produce very different results in terms of muscle retention and fat loss.

What macro split is best for weight loss?

A higher protein split (around 40% protein, 30% carbs, 30% fat) is generally recommended for weight loss as it helps preserve muscle mass, increases satiety, and has a higher thermic effect than carbs or fat. Use the custom sliders to fine-tune these ratios to your preference.

What is the difference between Mifflin-St Jeor and Katch-McArdle?

Mifflin-St Jeor uses your weight, height, age, and gender to estimate BMR. Katch-McArdle uses your lean body mass (calculated from body fat percentage) and is more accurate for people who know their body composition, especially those with above-average or below-average muscle mass.

Should I eat differently on training days?

Many people benefit from eating more carbohydrates on training days to fuel performance and recovery, and slightly fewer carbs on rest days. The training day split in this calculator shifts carbs up and fat down on training days while keeping protein constant.

How accurate is the projected timeline?

The timeline is a rough estimate based on the simple rule of 7,700 kcal per kg of body fat. In practice, weight loss slows over time due to metabolic adaptation, and results vary based on adherence, sleep, stress, and individual metabolism.

Macro Calculator

This advanced Macro Calculator works out your ideal daily intake of protein, carbohydrates, and fat based on your body stats, activity level, and goal. Switch between metric and imperial units, set custom macro ratios with interactive sliders, choose your deficit or surplus intensity, and get per-meal breakdowns for 2 to 6 meals. Enter your body fat percentage for a more accurate result using the Katch-McArdle formula, and compare all three goals side by side.

Enter Your Details

Units

Gender

Age

years

Weight

Height

Activity Level

Goal

Body Fat %

Optional. Enables the more accurate Katch-McArdle formula.

Calorie Deficit: 20%

5% (gentle)20% (moderate)35% (aggressive)

Number of Meals

Custom Macro Ratios

How It Works

Your macros are calculated in three steps. First, your Basal Metabolic Rate (BMR) is estimated using either the Mifflin-St Jeor equation (default) or the Katch-McArdle equation if you provide your body fat percentage. Then your Total Daily Energy Expenditure (TDEE) is calculated by multiplying BMR by an activity factor. Finally, your calorie target is adjusted by your chosen deficit or surplus percentage and split into protein (4 kcal/g), carbs (4 kcal/g), and fat (9 kcal/g). You can override the default macro ratios with custom sliders. Results include a per-meal breakdown, weekly totals, training vs rest day splits, a goal comparison table, and a projected weight-change timeline.

Quick Reference

Goal	Calorie Adjustment	Protein	Carbs	Fat
Fat Loss	Customisable deficit (default -20%)	40%	30%	30%
Maintenance	No change	30%	40%	30%
Muscle Gain	Customisable surplus (default +10%)	30%	45%	25%

Default percentages shown. Use the custom macro sliders to set your own ratios for any goal.

How This Is Calculated

Mifflin-St Jeor: BMR = (10 x weight kg) + (6.25 x height cm) - (5 x age) + 5 (male) or -161 (female) Katch-McArdle: BMR = 370 + (21.6 x lean body mass kg) TDEE = BMR x activity multiplier Target Calories = TDEE x goal adjustment Protein (g) = (Target Calories x protein%) / 4 Carbs (g) = (Target Calories x carbs%) / 4 Fat (g) = (Target Calories x fat%) / 9

BMR: = Basal Metabolic Rate - calories burned at complete rest
TDEE: = Total Daily Energy Expenditure - calories burned including activity
Lean mass: = Body weight minus fat mass (used by Katch-McArdle when body fat % is provided)
4 kcal/g: = Energy per gram of protein and carbohydrates
9 kcal/g: = Energy per gram of fat

Uses the Mifflin-St Jeor equation by default. When body fat percentage is entered, the Katch-McArdle equation is used instead as it accounts for lean body mass and is more accurate for those who know their body composition. Activity multipliers range from 1.2 (sedentary) to 1.9 (very active).

Frequently Asked Questions

What are macros?: Macros (macronutrients) are the three main nutrients your body needs in large amounts: protein, carbohydrates, and fat. Each provides energy (calories/kilojoules) and plays different roles in your body.
How much protein do I need?: For weight loss, aim for 1.6-2.2g of protein per kg of body weight to preserve muscle mass. For maintenance, 1.2-1.6g/kg is sufficient. For muscle gain, target 1.6-2.2g/kg. This calculator shows your protein intake in g/kg so you can check your targets at a glance.
Should I track macros or just calories?: Tracking macros gives you more control over body composition than tracking calories alone. Two diets with the same calories but different macro splits can produce very different results in terms of muscle retention and fat loss.
What macro split is best for weight loss?: A higher protein split (around 40% protein, 30% carbs, 30% fat) is generally recommended for weight loss as it helps preserve muscle mass, increases satiety, and has a higher thermic effect than carbs or fat. Use the custom sliders to fine-tune these ratios to your preference.
What is the difference between Mifflin-St Jeor and Katch-McArdle?: Mifflin-St Jeor uses your weight, height, age, and gender to estimate BMR. Katch-McArdle uses your lean body mass (calculated from body fat percentage) and is more accurate for people who know their body composition, especially those with above-average or below-average muscle mass.
Should I eat differently on training days?: Many people benefit from eating more carbohydrates on training days to fuel performance and recovery, and slightly fewer carbs on rest days. The training day split in this calculator shifts carbs up and fat down on training days while keeping protein constant.
How accurate is the projected timeline?: The timeline is a rough estimate based on the simple rule of 7,700 kcal per kg of body fat. In practice, weight loss slows over time due to metabolic adaptation, and results vary based on adherence, sleep, stress, and individual metabolism.

Related Tools

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