🥗Macro Calculator
See how a calorie intake splits into protein, carbs, and fat. Choose a preset ratio or set your own — an educational reference for understanding macronutrients.
Calories
Macro Split
This tool is a general reference for understanding how macronutrients divide up a given calorie intake. It is not medical or dietary advice. Please consult a registered dietitian or physician before making any significant change to your diet, calorie intake, or nutrition — especially if you have any health condition, are pregnant, or are managing a medical issue. Individual needs vary, and only a qualified professional can give advice tailored to you.
Free Macro Calculator Online
Wondering how your calories split into protein, carbs, and fat? Our free Macro Calculator breaks it down clearly. As an educational macro calculator online, it takes a calorie amount — one you enter yourself, or your estimated maintenance calories — and divides it into grams of each macronutrient based on the ratio you choose, showing the math behind every number.
Pick a balanced split, a higher-protein split, or set your own custom percentages (they just need to add up to 100%), and see exactly how many grams of protein, carbs, and fat that works out to. Each macronutrient is explained so you understand what the numbers mean rather than just chasing them. It's a reference for understanding macros — not a diet plan.
Enter your calories and choose a split to see your breakdown instantly. No sign-up, no downloads, no limits. For any real dietary change, please speak with a registered dietitian or physician. Learn more in the FAQ or About pages.
How This Macro Calculator Works
The calculation is straightforward: multiply your total calories by each macronutrient's percentage, then divide by its energy density. Carbohydrates and protein each provide 4 kcal per gram; fat provides 9 kcal per gram. So at 2,000 kcal with a 40/30/30 carb/protein/fat split, that's 200 g of carbs, 150 g of protein, and 66.7 g of fat.
The optional maintenance estimate uses the same Mifflin-St Jeor and Harris-Benedict formulas as the TDEE Calculator, so figures are consistent if you use both tools. This is an educational reference — for a personalised nutrition plan, consult a registered dietitian or physician.
About the Macro Calculator
Key features
Preset & custom splits
Choose from three common macro ratios — Balanced (40C/30P/30F), Higher-Protein (30C/40P/30F), or Low-Carb (20C/35P/45F) — or enter any custom percentages that sum to 100%.
Grams with kcal math shown
Displays grams and kilocalories for each macronutrient, with the calculation note so you can see exactly how each figure was derived — no black-box outputs.
Stacked proportion bar
A colour-coded bar shows the visual proportions of carbs, protein, and fat in your split, with a legend showing each percentage at a glance.
Optional maintenance estimate
Enable the maintenance estimate to get a TDEE figure from your height, weight, age, sex, and activity — using the same Mifflin-St Jeor or Harris-Benedict formulas as the TDEE Calculator — and apply it to the macro split in one click.
The macronutrient basics
Carbohydrates — 4 kcal/g
The body's primary energy source. Digested into glucose for use by the brain, muscles, and organs. Found in grains, fruit, vegetables, legumes, and dairy.
Protein — 4 kcal/g
Essential for building and repairing muscle, enzymes, hormones, and body structures. Found in meat, fish, eggs, dairy, beans, and soy. Used for fuel only when carbohydrate and fat are insufficient.
Fat — 9 kcal/g
A concentrated energy source, also essential for fat-soluble vitamins (A, D, E, K), cell membranes, and hormones. Fat provides more than twice the energy per gram of carbs or protein.
What this tool does and doesn't do
It does: take a calorie input (manual or estimated), apply a chosen macro ratio, output grams of carbs, protein, and fat with the kcal-per-gram math visible, and explain what each macronutrient is.
It doesn't: prescribe a calorie target for weight loss or gain, include a goal selector or deficit/surplus pathway, set target weights, or produce any "cut/bulk plan". There are no aggressive-cut presets or very-low-calorie pathways — those decisions belong with a qualified professional.
Important: educational reference only
If you ever find yourself preoccupied with restricting food or with your weight, please consider reaching out to a qualified professional for support.
Have questions? See the Macro Calculator FAQ.
Frequently Asked Questions
What are macros?
"Macros" are macronutrients — protein, carbohydrates, and fat — the three nutrients that provide the calories (energy) in your food. Each provides a set amount of energy per gram: protein and carbs about 4 kcal, fat about 9 kcal.
How does the macro calculator work?
You provide a calorie amount — either entered directly or pulled from your estimated maintenance calories — and choose a protein/carb/fat split. The tool multiplies your calories by each percentage, then divides by the energy per gram (4 for carbs and protein, 9 for fat) to give grams of each macronutrient. For example, 2,000 kcal at 40% carbs / 30% protein / 30% fat gives 200 g of carbs, 150 g of protein, and approximately 66.7 g of fat.
Is this calculator free to use?
Yes, it's completely free with no sign-up, downloads, or limits. Use it as often as you like.
Does it tell me how much to eat to lose or gain weight?
No — and that's intentional. This is an educational reference that shows how a calorie figure divides into macros. It doesn't prescribe a calorie target for weight change. Individual targets should be set with a registered dietitian or physician.
Can I set my own macro ratios?
Yes. Choose from common presets — Balanced (40% carbs / 30% protein / 30% fat), Higher-Protein (30% carbs / 40% protein / 30% fat), or Low-Carb (20% carbs / 35% protein / 45% fat) — or select Custom and enter your own percentages for protein, carbs, and fat. They simply need to add up to exactly 100%.
What's a "good" macro split?
There's no single right answer — it depends on the person, their activity, preferences, and any medical needs. The presets reflect common general-population ratios, but a registered dietitian or physician can advise what's appropriate for you specifically.
Where does the calorie number come from?
You can type in any calorie amount, or enable the "Use estimated maintenance calories" option. That shows a built-in TDEE estimate based on your height, weight, age, sex, and activity level — using the same Mifflin-St Jeor or Harris-Benedict formula as the TDEE Calculator. It's a general estimate, not a prescription.
Is my data stored anywhere?
No. Your inputs are processed directly in your browser and are never stored or sent to a server, keeping your information completely private.
Does it work on mobile devices?
Yes, the tool is fully responsive and works on smartphones, tablets, and desktops, with the layout fitting the screen without overflow.
Should I base a diet on these numbers?
No. This is a reference for understanding macros, not medical or dietary advice. Please consult a registered dietitian or physician before making any significant change to your diet or nutrition — especially if you have a health condition, are pregnant, or are managing a medical issue. If you ever find yourself preoccupied with food or restriction, consider reaching out to a qualified professional for support.