Macro Calculator

Calculate your daily macros — protein, carbs, and fat in grams — from your calorie target and diet plan, with balanced, low-carb, high-protein, and keto splits.

Sex
Height cm
ft in
Activity level
  • Sedentary — little or no exercise
  • Light — exercise 1–3 days/week
  • Moderate — exercise 3–5 days/week
  • Active — exercise 6–7 days/week
  • Very active — hard exercise or physical job
Goal
  • Maintain weight
  • Lose weight (−0.5 kg/week)
  • Gain weight (+0.5 kg/week)
Diet plan (protein / carbs / fat)
  • Balanced — 30 / 40 / 30
  • Low-carb — 40 / 20 / 40
  • High-protein — 40 / 35 / 25
  • Keto — 25 / 5 / 70
Calorie formula
  • Mifflin-St Jeor (recommended)
  • Harris-Benedict
  • Katch-McArdle (uses body fat)
Daily calorie target —kcal
Protein — — · — kcal
Carbs — — · — kcal
Fat — — · — kcal

Grams from your daily calorie target, split by your diet plan (4 · 4 · 9 kcal/g).

Your macros — protein, carbohydrate, and fat — are the three nutrients that provide energy. A calorie target tells you how much to eat; your macro split tells you what those calories should be made of. This calculator does both: it estimates your daily calories, then divides them into grams of each macro.

How your macros are calculated

The calculator works in two steps:

  1. Calories. It estimates your Basal Metabolic Rate with the Mifflin-St Jeor equation, multiplies by an activity factor to get your total daily energy (TDEE), and adjusts for your goal (maintain, lose, or gain).
  2. The split. It divides those calories among the three macros using your diet plan’s percentages, then converts each share to grams using the standard energy densities:
MacronutrientEnergyGrams from calories
Protein4 kcal/gkcal ÷ 4
Carbohydrate4 kcal/gkcal ÷ 4
Fat9 kcal/gkcal ÷ 9

Diet plans

Each plan is a percentage of total calories from protein / carbs / fat:

PlanProteinCarbsFat
Balanced30%40%30%
Low-carb40%20%40%
High-protein40%35%25%
Keto25%5%70%

All four sit inside — or, for keto, deliberately outside — the Institute of Medicine’s Acceptable Macronutrient Distribution Ranges (45–65% carbs, 20–35% fat, 10–35% protein), which describe intakes associated with a reduced risk of chronic disease while meeting nutrient needs.

Worked example

A 2,000-calorie day on a balanced 30/40/30 split works out to:

  • Protein: 30% of 2,000 = 600 kcal ÷ 4 = 150 g
  • Carbs: 40% of 2,000 = 800 kcal ÷ 4 = 200 g
  • Fat: 30% of 2,000 = 600 kcal ÷ 9 ≈ 67 g

Using your numbers

Protein is the macro most worth hitting consistently — it preserves muscle when you’re losing fat and supports muscle growth when you’re gaining. Carbs and fat are more flexible; shift them to suit your appetite, energy, and preferences as long as your calorie total stays roughly on target.

Frequently asked questions

What are macros?

"Macros" is short for macronutrients — the three nutrients that supply energy: protein, carbohydrate, and fat. Protein and carbs provide about 4 calories per gram, and fat about 9. Tracking macros means hitting target grams of each, not just a calorie total.

How does this calculator work out my macros?

First it estimates the calories you need using the Mifflin-St Jeor equation and your activity level and goal. Then it divides those calories between protein, carbs, and fat using your chosen diet plan's percentages, and converts each share into grams (4 kcal/g for protein and carbs, 9 kcal/g for fat).

Which macro split should I choose?

A balanced 30/40/30 split (protein/carbs/fat) works well for most people. Choose higher-protein or low-carb if you're building muscle or losing fat, and keto only if you specifically want a very-low-carb approach. Protein is the split that matters most for body composition.

Do I have to hit my macros exactly?

No. Treat the numbers as daily targets to aim near, not exact quotas. Getting close to your protein target and staying near your calorie total captures most of the benefit; carb and fat grams can flex day to day.

References