Enter your daily calorie target and this tool works out how many grams of protein, carbohydrate and fat that maps to. Choose a ready-made ratio — balanced, low-carb, high-protein or keto — or type your own split. It uses the standard energy values (4 kcal per gram of protein and carbs, 9 for fat) and calculates on your device.
Enter your daily calories to see the macro breakdown.
This is a general educational estimate, not nutrition or medical advice. Individual needs vary — consult a dietitian or doctor for a personalised plan.
How it works
Each macronutrient carries a fixed amount of energy: protein and carbohydrate release about 4 kcal per gram, fat about 9 kcal per gram. The tool takes your calorie total, applies the percentage split you chose, and divides each slice by its per-gram value to get grams. So a 2,000 kcal day at 30% protein means 600 kcal from protein, which is 150 g.
The presets are common starting points, not rules: balanced (30/40/30), low-carb (40/25/35), high-protein (40/35/25) and keto (20/5/75), written as protein/carbs/fat. The custom mode lets you set protein and carb percentages directly; fat is whatever is left so the three always add up to 100%. It does not decide your calorie target — pair it with the calorie calculator for that.
Practical examples
Balanced 2,000 kcal day
At the balanced 30/40/30 split, 2,000 kcal gives 150 g protein, 200 g carbs and about 67 g fat. A reasonable everyday template for someone maintaining weight.
Higher protein for training
Someone lifting weights on 2,600 kcal picks high-protein (40/35/25): 260 g protein, 228 g carbs and 72 g fat — more protein to support recovery while keeping carbs for energy.
A custom keto-leaning split
Set custom to 25% protein and 10% carbs on 1,800 kcal: fat fills the remaining 65%, giving 113 g protein, 45 g carbs and 130 g fat.
Frequently asked questions
What are macronutrients?
The three nutrients that supply energy: protein, carbohydrate and fat. Everything you eat is some combination of them (plus water, fibre, vitamins and minerals). "Counting macros" means tracking grams of each rather than only total calories.
How do I know my calorie target?
This tool starts from a number you already have. To estimate it, use a TDEE/calorie calculator: it works out maintenance calories from your weight, height, age, sex and activity, then adds or subtracts for a goal. Feed that figure in here.
Which split should I choose?
Balanced suits most people. Higher-protein ratios help when you are training or trying to keep muscle while losing fat. Low-carb and keto shift energy to fat and suit some people’s preferences or medical guidance. There is no single best ratio — total calories and protein matter most.
Why is fat 9 calories a gram but protein and carbs only 4?
Fat is a more energy-dense molecule, so a gram of it releases roughly twice the energy of a gram of protein or carbohydrate when metabolised. These are the Atwater factors used on nutrition labels.
How much protein do I actually need?
General guidance is around 1.6–2.2 g per kg of body weight per day for people who train, less for sedentary adults. Check whether the grams this tool gives you land in that range and adjust the split if not.
Should I hit these numbers exactly every day?
No. Treat them as targets to aim near, not limits to obsess over. Being within 10–15 g on each macro most days is more sustainable — and just as effective — as chasing exact figures.
Does the calculator include fibre or alcohol?
No. Fibre is a carbohydrate that contributes little usable energy, and alcohol (7 kcal/g) is not a macronutrient the tool tracks. If you drink, account for those calories separately.
Can I use this to lose or gain weight?
Weight change is driven by your total calorie target, not the split. Set a target below maintenance to lose or above it to gain, then use the split to decide how those calories are made up. Keeping protein high while cutting calories helps preserve muscle.
Why don’t the gram figures multiply back to exactly my calories?
Grams are rounded to whole numbers for practicality, so re-multiplying can be off by a few calories. The percentages and calorie sub-totals shown are exact; the grams are the rounded, usable version.
Is my data sent anywhere?
No. The calculation happens entirely in your browser. Nothing you type is uploaded, and analytics never receives your numbers.
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