Macronutrient Calculator

1. Enter your daily calorie target.
2. Pick a diet type: balanced, low-carb, high-protein or keto.
3. Read your daily grams of protein, carbohydrate and fat.
4. Switch diet types to compare splits at the same calories.

Here is what each result means:

Macronutrients, or macros, are the three nutrients your body needs in large amounts: protein, carbohydrate and fat. Together they supply all your energy, measured in calories, and each also has jobs beyond fuel, from building muscle to supporting hormones.

Tracking macros, not just calories, helps you eat enough protein, manage energy and match your food to a goal such as fat loss or muscle gain. The right split depends on your body, activity and health, so treat these presets as sensible starting points rather than strict rules.

It takes your calories, applies the percentage split for your chosen diet, then converts each share to grams using the calories-per-gram of each macro.

1. Multiply your calories by each macro percentage.
2. Divide protein and carb calories by 4, and fat calories by 9.
3. The results are your daily grams of each macro.

Suppose your target is 2,000 calories on a balanced 40/30/30 split (carbs, protein, fat).

Calculation: protein = 2,000 x 30% / 4 = 150 g. Carbs = 2,000 x 40% / 4 = 200 g. Fat = 2,000 x 30% / 9 = 67 g.

Switch to a low-carb 25/35/40 split and the same 2,000 calories become about 175 g protein, 125 g carbs and 89 g fat.

These are the presets this calculator uses, expressed as carbs / protein / fat.

These are general templates. Athletes, people managing blood sugar and those with medical conditions may need different ratios set with a professional.

The grams shift with your calories and your goal, so revisit them as things change.

Your Calorie Target

More calories mean more grams across the board. Get the calorie number right first, since everything scales from it.

Your Goal

Fat loss often favours higher protein to preserve muscle, while endurance training leans on more carbs for fuel.

Body Weight and Activity

Protein needs are often set per kilogram of body weight, so heavier or very active people may need more than a flat percentage suggests. Needs also shift with life stage, rising in pregnancy and changing with age.

These approaches to eating overlap but answer different questions.

Macros build on a calorie target, so find your daily calories with the calorie calculator before splitting them.

Building Muscle

Higher protein supports muscle repair and growth alongside training, typically at the upper end of the recommended range.

Losing Fat

Keeping protein high while in a calorie deficit helps protect muscle as you lose weight.

Managing Energy

Balancing carbs and fat can steady energy through the day and around workouts.

1. Setting Macros Before Calories

Macros are a split of your calorie total. Guessing calories makes every gram figure wrong.

2. Chasing Extreme Ratios

Very low carb or very high fat is not automatically better. The best split is one you can sustain and that fits your health.

3. Ignoring Protein Quality and Fibre

Hitting grams is not the whole story. Food quality, fibre and micronutrients still matter.

4. Forgetting to Adjust

As weight, activity or goals change, recalculate. A fixed split can drift out of date.

5. Treating Presets as Medical Advice

Conditions such as diabetes or kidney disease need tailored macros. Work with a professional.

The math is exact for the calories and split you enter, but the presets are general and not a personalised plan.

Protein is the macro most people under-eat, and it does the most work beyond energy. It supplies the amino acids that build and repair muscle, skin, enzymes and hormones, and it is the most filling of the three macros, which helps with appetite control.

General guidance for active adults is roughly 1.2 to 2.0 grams of protein per kilogram of body weight per day, with the upper end favoured when building muscle or losing fat, since higher protein helps protect muscle in a calorie deficit. Someone weighing 70 kg would therefore target somewhere between about 85 and 140 grams. A percentage split is a simpler starting point, but if you have a body-composition goal, it is worth checking that your protein in grams lands in this per-kilogram range and adjusting the split if it does not.

Spreading protein across the day, rather than loading it all at dinner, appears to support muscle maintenance a little better, so aim for a solid source at each main meal.

Carbohydrates are the body preferred energy source, especially for the brain and for higher-intensity exercise. They are stored in muscles and the liver as glycogen, which fuels training and is topped up by the carbs you eat.

The quality of carbs matters as much as the quantity. Minimally processed sources such as vegetables, fruit, legumes and whole grains bring fibre, vitamins and a slower, steadier release of energy, while refined sugars and heavily processed carbs deliver quick energy with little else. A macro target tells you how many grams to eat; it does not tell you to hit them with candy. Prioritising fibre-rich carbs keeps you fuller and steadies blood sugar within the same gram total.

Active people and endurance athletes generally need more carbs, while those managing blood sugar or following a low-carb approach deliberately keep them lower and lean more on fat for fuel.

Fat was demonised for decades, but it is essential. It supports hormone production, helps you absorb the fat-soluble vitamins A, D, E and K, protects organs and provides a concentrated, long-lasting energy source at 9 calories per gram.

As with carbs, the type matters. Unsaturated fats from sources such as olive oil, nuts, seeds, avocado and oily fish support heart health, while very high intakes of saturated fat and any trans fat are best limited. A macro plan sets your total fat grams; filling most of them from unsaturated sources is the healthier way to hit the number.

Because fat is calorie-dense, it is easy to overshoot by eye, so it is often the macro that benefits most from weighing or measuring while you learn portion sizes.

The best split depends on what you are trying to do. These are common starting points, always built on a calorie target set for the goal.

Notice that protein stays relatively high across almost every goal. The main lever that changes is the balance of carbs and fat, and how that total sits against your calories.

Numbers on a screen are easy; food is where it gets practical. The simplest way to hit a split is to build each meal around a protein source, then add carbs and fat to taste and target.

Lean meats, fish, eggs, dairy, tofu, tempeh and legumes anchor protein. Rice, oats, potatoes, bread, fruit and vegetables cover carbs. Oils, nuts, seeds, avocado and the fat within protein foods make up fat. A plate with a palm-sized protein portion, a fist of carbs and a thumb of added fat is a rough, no-weighing way to approximate a balanced meal.

When you first track, weighing food for a week or two calibrates your eye, after which many people estimate well enough without weighing every meal. Consistency over the week matters more than precision at any single meal.

A macro target is a starting hypothesis, not a fixed prescription. Your body responds, your weight changes, and the numbers that worked at the start may need a nudge.

If progress stalls for two to three weeks, the usual first move is to revisit calories rather than obsess over the split, since energy balance drives weight change. If you are losing muscle or strength while dieting, raising protein is the priority. If training feels flat, adding carbs often helps. Recalculate whenever your weight shifts meaningfully, since both your calorie needs and your per-kilogram protein target move with it.

Treat each adjustment as an experiment, give it a couple of weeks, and judge it by the trend in weight, measurements, performance and how you feel.

Plant-based eaters can hit any macro split, but protein takes a little more planning because many plant proteins come packaged with carbs or fat.

Legumes, tofu, tempeh, edamame, seitan, and higher-protein grains and pseudo-grains all help, and soy foods in particular provide a complete amino-acid profile. Because beans and lentils carry carbohydrate alongside protein, a higher-protein plant plan often naturally lands in a moderate-carb rather than low-carb split, which is worth accounting for when you pick a target. A protein supplement such as soy or pea protein can close the gap for those with high protein goals.

The same food-quality principles apply: build meals around whole plant foods, and the fibre and micronutrients come along with the macros.

Nutrient timing, the idea that when you eat matters, gets a lot of attention, but for most people it is a minor factor next to hitting your total calories and macros for the day.

There is a reasonable case for spreading protein fairly evenly across meals to support muscle maintenance, and for having some carbohydrate around harder training sessions to fuel and recover from them. Beyond that, the strict anabolic window that once dominated advice has been shown to be much wider than believed, so a protein feeding within a few hours of training is plenty for most goals. If you train fasted or late, adjust to what lets you perform and recover; there is no single correct schedule.

In short, get your daily totals right first. Timing is a refinement worth considering only once the bigger levers of calories, protein and food quality are consistent.

Fibre is a type of carbohydrate, so it sits inside your carb total rather than as a separate macro, but it deserves its own attention. It feeds gut bacteria, slows digestion for steadier energy, lowers cholesterol and, importantly for anyone managing weight, keeps you full.

General guidance is around 25 to 38 grams a day for adults, yet many people fall well short. Two macro plans with identical carb grams can differ enormously in fibre depending on whether those carbs come from vegetables, fruit, legumes and whole grains or from refined sources. Aiming for fibre-rich carbs is one of the simplest ways to make the same macro target healthier and more satisfying.

If you increase fibre, do it gradually and drink enough water, since a sudden jump can cause bloating.

Alcohol is sometimes called the fourth macro because it provides energy, about 7 calories per gram, more than protein or carbs and close to fat. It is not tracked by this calculator, but it still counts toward your day.

Beyond the calories, alcohol offers no useful nutrients, can blunt muscle protein synthesis and recovery, and tends to loosen food choices, so its real cost to a nutrition plan is often larger than the drink itself. If you drink, the practical approach is to account for the calories, keep protein and overall intake on track around it, and treat it as a conscious trade rather than a free extra.

Your body gives feedback, and learning to read it saves a lot of guesswork.

Persistent hunger and low energy on a fat-loss plan can signal that the deficit is too aggressive or protein and fibre are too low. Losing strength or muscle while dieting usually means protein should rise. Feeling flat or struggling through workouts often points to too few carbs around training. Weight that has not moved for two to three weeks, in either direction, is a sign to revisit calories before touching the split. And if you simply cannot stick to a plan, that is data too: the most effective macros are the ones you can actually follow.

Treat each change as a small experiment, hold it for a couple of weeks, and judge it by the trend rather than a single day.

Macros are only half the nutrition story. Micronutrients, the vitamins and minerals your body needs in small amounts, do not provide energy but are essential for everything from immunity to bone health to turning the food you eat into usable fuel.

You can hit your macros perfectly and still fall short on iron, calcium, vitamin D, magnesium or the many others, especially if your food choices are narrow. This is the strongest argument for building your macro grams out of varied, whole foods rather than a handful of processed products that happen to fit the numbers. Plenty of vegetables and fruit, a range of protein sources, whole grains and some healthy fats will cover most micronutrient needs without any tracking.

If your diet is restricted, for example vegan, very low calorie or excluding food groups, it is worth checking whether a specific nutrient needs attention, sometimes with a supplement, ideally guided by a professional.

To make the numbers concrete, here is a rough day built around a balanced 2,000-calorie target of about 150 g protein, 200 g carbs and 67 g fat. It is illustrative, not a prescription.

Notice that every meal is anchored by a protein source, carbs cluster around the day active hours, and fat comes largely from whole-food and unsaturated sources. Building your own day on the same skeleton, with foods you enjoy, is usually more sustainable than following someone else exact menu.

Start with your daily calorie target, split it into percentages for carbs, protein and fat, then convert to grams. Protein and carbs are 4 calories per gram and fat is 9, so divide each macro calories by those numbers.

A balanced 40/30/30 split of carbs, protein and fat works for many people. Higher-protein or lower-carb splits can suit fat loss or blood-sugar goals, but the best ratio is one that fits your health and that you can sustain.

Protein and carbohydrate each provide about 4 calories per gram, while fat provides about 9. Alcohol, which is not tracked here, provides about 7 calories per gram.

Common guidance is roughly 1.2 to 2.0 grams of protein per kilogram of body weight for active adults, higher within that range for building muscle. A percentage split is a simpler starting point you can refine.

A ketogenic split is very high fat, moderate protein and very low carb, often around 70 percent fat, 25 percent protein and 5 percent carbs. It is a medical-style diet for some people, so get advice before starting.

No. Aim to land close to your targets over the day and week. Consistency and food quality matter more than hitting every gram precisely.

Calories drive weight change, while macros shape body composition and energy. If you have a performance or muscle goal, macros add useful control on top of a calorie target.

Yes, if your calorie target is set for a deficit. Keeping protein relatively high helps protect muscle while you lose fat. Set the calorie number first, then split it here.

Yes, a great deal. Two meals with identical macros can differ hugely in fibre, vitamins and how full they leave you. Hitting your grams from mostly whole, minimally processed foods is healthier and easier to sustain than hitting them with processed options.

Recalculate whenever your weight changes meaningfully or your goal shifts, since both your calorie needs and your per-kilogram protein target move with your body. If progress stalls for two to three weeks, that is another good time to review.

Not forever. Weighing for a week or two calibrates your eye, after which many people estimate well using hand or plate portions. Consistency across the week matters more than precision at any single meal.

No. The calculation runs entirely in your browser and nothing you enter is stored or sent anywhere unless you choose to Save a result, which stays only in this browser.

• Dietary proteins (NIH MedlinePlus).
• Carbohydrates in your diet (NIH MedlinePlus).
• The Nutrition Source: what should you eat (Harvard T.H. Chan School of Public Health).